ࡱ>  l \pThe Free Software Foundation B=PF0*8X@"1 Helvetica1Courier1 Courier New1 Courier New1 Helvetica$#,##0_);($#,##0)$#,##0_);[Red]($#,##0)$#,##0.00_);($#,##0.00)$#,##0.00_);[Red]($#,##0.00)-**_($* #,##0_);_($* (#,##0);_($* "-"_);_(@_)*)'_(* #,##0_);_(* (#,##0);_(* "-"_);_(@_)5,2_($* #,##0.00_);_($* (#,##0.00);_($* "-"??_);_(@_)2+/_(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(@_)2$#,##0.00;[Red]$#,##0.003$#,##0.00;[Red]($#,##0.00)4$#,##0;[Red]($#,##00)50.00%;[Red](0.00%)6 0%;[Red](0%)7#,##0.00;[Red](#,##0.00)8#,##0;[Red](#,##0)                + ) , *   Ј ~~ ؈ ~~#؈ ~~ ؈ ~~8#܈ ~~"؈ ~~9"܈ ~~4#܈ ~~9#܈ ~~83ffff̙̙3f3fff3f3f33333f33 NO TITLE&FREPORT OF INDEPENDENT REGISTERE&#REPORT OF INDEPENDENT REGIS (1)&^1REPORT OF INDEPENDENT REGIS (2)&<REPORT OF INDEPENDENT REGIS (3)&DREPORT OF INDEPENDENT REGIS (4)&[REPORT OF INDEPENDENT REGIS (5)&sREPORT OF INDEPENDENT REGIS (6)&}REPORT OF INDEPENDENT REGIS (7)&[REPORT OF INDEPENDENT REGIS (8)&REPORT OF INDEPENDENT REGIS (9)&REPORT OF INDEPENDENT REGI (10)&REPORT OF INDEPENDENT REGI (11)&REPORT OF INDEPENDENT REGI (12)&REPORT OF INDEPENDENT REGI (13)&REPORT OF INDEPENDENT REGI (14)&REPORT OF INDEPENDENT REGI (15)&.REPORT OF INDEPENDENT REGI (16) l  # dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } 6} $ }  #    $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011NO TITLE      Page   / 'Report of Independent Registered Public ~ Accounting Firm.&Statements of Net Assets Available for~ 1)Benefits as of December 31, 2021 and 20094,Statement of Changes in Net Assets Available~ 0(for Benefits for the Year Ended December31, 2010%Notes to Financial Statements~ 0(Schedule H; Line 4i - Schedule of Assets~ F5-(Held At End of Year) as of December 31, 2010 Signatures~ NIndex to Exhibits~ RDJlznJ&rNW#6N !"$ ____________________________1!)Created by Morningstar Document Research.0"(http://documentresearch.morningstar.com/ (=PF0*8X> @""!!  l  ! dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ } y} $ } y     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC December 31,   ~ j ~ f       ! Investments at fair value~ %< ~ &i0* "Notes receivable from participants ~ B  ~ :]~ ~=~ N13+Unallocated accrued administrative expenses~ ^U~  .&Net assets reflecting all investments,~ >=~ bZ1at fair value.&Adjustment from fair value to contract5-value for fully benefit-responsive investment-%contracts held by a common/collective~ ^6~ vtrust)!Net assets available for benefits~  =~ .Ѹ1$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/:sg[Os&ljF)=PF0*8X> @       l  !/S0 dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ }  !    $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC7 /Additions to net assets available for benefits:   5 -Net appreciation in fair value of investments~ RvK  Employer contributions ~ B` # Participants' contributions ~ 6$Interest and dividend income~ :h Rollovers~ IOther additions~ OTotal additions~ r0(Deductions from net assets available for benefits:%Distributions to participants~ Administrative expenses~  Total deductions~ 0(Net increase in net assets available for~ n9 benefits4,Net assets available for benefits, beginning~ .Ѹ1of year.&Net assets available for benefits, end~  =of year$____________________________1)Created by Morningstar Document Research.D1 lsg[OUr7ahB# 0 (http://documentresearch.morningstar.com/H=PF0*8X> @       l  I; dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $                         $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC December 31,    ~ j ~ f          Vanguard PRIMECAP Fund~ rv ~ |, $Pioneer Natural Resources Stock Fund~ 3 ~ Vanguard 500 Index Fund~ 7~ B Vanguard Windsor II Fund~ ߛ~ V( Vanguard Prime Money Market Fund~ j~ ^0Sarofim Equity Fund~ Z;/'American Funds Euro Pacific Growth Fund~ .+$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/2usg[OCV e=PF0*8X> @         l  AD dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ } } $     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC Mutual funds~ .w, $Pioneer Natural Resources Stock Fund ~ 5   Common/collective trusts ~ 6^      5 -Net appreciation in fair value of investments~ RvK $____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(#Tsg[O}A=PF0*8X> @J      l  "YxZ dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ } } $ } } $ } } $ }  "    $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC1)Fair Value Measurements at Reporting Date     Using     Quoted Prices in  Significant Other   Significant " Fair Value at December 31,     Active Markets for   Observable   Unobservable ~ j     Identical Assets  Inputs  Inputs (Level 1) (Level 2)   (Level 3)Assets:    Mutual funds:    Money market fund~ j $-   $- ~ j Bond funds~ 2Jk~   ~   ~ 2JkBalanced funds~ k~   ~   ~ kDomestic stock funds~ zf~   ~   ~ zf!International stock funds~ ~   ~   ~ Real estate fund~ *#~   ~   ~ *#!Common/collective trusts:    Sarofim Equity Fund (a)~ ~ ^  ~   ~ ^/'Vanguard Retirement Savings Trust V (b)~ ~ *  ~   ~ *,$Pioneer Natural Resources Stock Fund~ 3~   ~   ~ 3~ "6~ sa   $- ~ %<    $____________________________Dlsg[O1"O[P5 !1 )Created by Morningstar Document Research.0!(http://documentresearch.morningstar.com/=PF0*8X> @:'!!             l  "pq dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ } } $ } } $ } } $ }  "    $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC1)Fair Value Measurements at Reporting Date     Using     Quoted Prices in $ Significant Other Observable   Significant " Fair Value at December 31,    + #Active Markets for Identical Assets  Inputs   Unobservable ~ f      (Level 1)   (Level 2)  Inputs   (Level 3)Assets:    Mutual funds:    Money market fund~ ^0 $-   $- ~ ^0 Bond funds~ 6R~   ~   ~ 6RBalanced funds~ O~   ~   ~ ODomestic stock funds~ Z:w~   ~   ~ Z:w!International stock funds~ j~   ~   ~ jReal estate fund~ "~   ~   ~ "!Common/collective trusts:    Sarofim Equity Fund (a)~ ~ Z;  ~   ~ Z;/'Vanguard Retirement Savings Trust V (b)~ ~ C  ~   ~ C,$Pioneer Natural Resources Stock Fund~ ~   ~   ~ ~ s+~    $- ~ &i0    $____________________________Dlsg[O5A6 !1 )Created by Morningstar Document Research.0!(http://documentresearch.morningstar.com/=PF0*8X> @*%!!             l  } dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ } %} $ } } $ }      $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC December 31,  ~ j ~ f       1 )Net assets available for benefits per the~  = ~ .Ѹ1) !accompanying financial statements.&Adjustment from fair value to contract( value for certain fully benefit-'responsive investment contracts~ ~ 6 2*Net assets available for benefits per Form~ >=~ bZ1~ U$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/2-sg[O.gJ<0=PF0*8X> @       l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $ }      $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC0 (Net increase in net assets available for ~ n9 / 'benefits per the accompanying financial  statements. &Adjustment from fair value to contract  ~ r@2*value for certain fully benefit responsive!investment contracts, net"Net increase per Form 5500~ y) $____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/0sg[O0YMA=PF0*8X> @b       l  Dk dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } } $ }  '} $ } :} $ }  D    $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC (c)   (b) 4 ,Description of investment including maturity   (e)  % Identity of issuer, borrower, + #date, rate of interest, collateral,   Current (a)  lessor, or similar party  par or maturity value   Value         *( Vanguard Fiduciary Trust Company/'Vanguard PRIMECAP Fund - 555,876 shares~ rv *( Vanguard Fiduciary Trust Company0(Vanguard 500 Index Fund - 212,081 shares~ 7 *( Vanguard Fiduciary Trust Company1)Vanguard Windsor II Fund - 753,060 shares~ ߛ *( Vanguard Fiduciary Trust Company*"Vanguard Prime Money Market Fund -16,579,290 shares~ j *( Vanguard Fiduciary Trust Company80Vanguard Retirement Savings Trust V - 11,104,225~ *sharesAmerican Funds/'American Funds Euro Pacific Growth Fund -~ ş270,559 shares *( Vanguard Fiduciary Trust Company( Vanguard Total Bond Market IndexFund - 918,122 shares~ Q *( Vanguard Fiduciary Trust Company+#Vanguard Intermediate-Term TreasuryFund -~ f 755,705 shares *( Vanguard Fiduciary Trust Company1)Vanguard Wellington Fund - 230,601 shares~ ҹ"Sentinel Group Funds, Inc.-%Sentinel Small Company Fund - 832,825~ shares *( Vanguard Fiduciary Trust Company0(Vanguard Total International Stock IndexDlsg[OZ u&)|dXb !"#$%&'()*+,-./0123456789:;<=>?     Fund -  ~ J!!!!!343,809 shares "*"(" Vanguard Fiduciary Trust Company"/"'Vanguard Inflation-Protected Securities"""#####Fund - 403,726 shares##~ #V@ $*$($ Vanguard Fiduciary Trust Company$.$&Vanguard Target Retirement 2020 Fund -$$$%%%%%219,176 shares%%~ %2' &*&(& Vanguard Fiduciary Trust Company&.&&Vanguard Target Retirement 2015 Fund -&&&'''''355,137 shares''~ '6 (*((( Vanguard Fiduciary Trust Company(.(&Vanguard Target Retirement 2025 fund -((()))))330,436 shares))~ )څ**&*Franklin Templeton Investments*,*$Templeton Global Bond Fund - 273,992**~ *D+++++shares ,*,(, Vanguard Fiduciary Trust Company,.,&Vanguard Total Stock Market Index Fund,,,---- ----~ -.....114,503 shares /*/(/ Vanguard Fiduciary Trust Company/./&Vanguard Target Retirement 2010 Fund -///00000150,387 shares00~ 0 1*1(1 Vanguard Fiduciary Trust Company1.1&Vanguard Target Retirement 2035 fund -11122222248,984 shares22~ 2333OppenheimerFunds, Inc.3-3%Oppenheimer Developing Markets Fund -3334444490,004 shares44~ 4% 5*5(5 Vanguard Fiduciary Trust Company5.5&Vanguard Target Retirement 2005 fund -55566666221,447 shares66~ 6. 7*7(7 Vanguard Fiduciary Trust Company7-7%Vanguard Extended Market Index Fund -7778888860,139 shares88~ 8r999Loomis Sayles909(Loomis Sayles Bond Fund - 152,688 shares99~ 9 :*:(: Vanguard Fiduciary Trust Company:.:&Vanguard Target Retirement 2030 Fund -::~ :x;;;;;90,695 shares <*<(< Vanguard Fiduciary Trust Company<.<&Vanguard Target Retirement 2045 fund -<<<=====136,000 shares==~ =p>>>>>>>>?D@lN/qZF] xaL @ABC@$A____________________________1B)Created by Morningstar Document Research.0C(http://documentresearch.morningstar.com/ <=PF0*8X> @"CCBBAA l  )% dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } $} $ } m)} $ } 2} $ } y )    $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLIC *( Vanguard Fiduciary Trust Company.&Vanguard Target Retirement 2040 Fund -~ f     78,394 shares   PIMCO 0 (PIMCO Total Return Fund - 154,183 shares  ~ f   Prudential Jennison 0 (Jennison Natural Resources Fund - 26,069  ~ *Z     shares *( Vanguard Fiduciary Trust Company.&Vanguard Target Retirement 2050 Fund -~ `I56,177 sharesT. Rowe Price2*T. Rowe Price Mid-Cap Growth Fund - 19,902~ GsharesRoyce*"Royce Premier Fund - 52,920 shares~ >@Columbia Acorn Funds2*Columbia Acorn International Fund - 17,273~ 2$+shares JP Morgan0(JP Morgan Small Cap Equity Fund - 19,154~ f*sharesInvesco,$AIM Real Estate Fund - 27,472 shares~ *#Royce/'Royce Total Return Fund - 31,485 shares~ &E *( Vanguard Fiduciary Trust Company+#Vanguard Target Retirement Income -~ r32,973 sharesArtisan Funds2*Artisan Mid Cap Value Fund - 14,948 shares~ Q *( Vanguard Fiduciary Trust Company.&Vanguard Target Retirement 2055 Fund -~   32 sharesFayez Sarofim & Co.,$Sarofim Equity Fund - 167,356 shares~ ^ *)!Pioneer Natural Resources Company.&Pioneer Natural Resources Stock Fund -~ 3835,770 unitsDlsg[O]1Fd"$U!?Q !"#$%&'( * * "Notes receivable from participants 0 (Interest rates range from 4.25% to 9.25%   !!!!!with various maturities!!~ !B""""""""######~ #~=$%$&____________________________1')Created by Morningstar Document Research.0((http://documentresearch.morningstar.com/7U|&=PF0*8X> @"((''&&## l  4 dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Larry N. Paulsen   Larry N. Paulsen  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(Tsg[OY=PF0*8X> @ l  M dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Richard P. Dealy   Richard P. Dealy  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(Tsg[OY=PF0*8X> @ l  f dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Mark H. Kleinman   Mark H. Kleinman  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(Tsg[OY=PF0*8X> @ l  { dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Kerry D. Scott   Kerry D. Scott  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(Tsg[O] =PF0*8X> @ l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (15)!REPORT OF INDEPENDENT REGI (16)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Susan A. Spratlen   Susan A. Spratlen  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(Tsg[OW=PF0*8X> @ l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (16)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Paul McDonald   Paul McDonald  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(Tsg[O_=PF0*8X> @ l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/?? NO TITLE!REPORT OF INDEPENDENT REGISTERE!REPORT OF INDEPENDENT REGIS (1)!REPORT OF INDEPENDENT REGIS (2)!REPORT OF INDEPENDENT REGIS (3)!REPORT OF INDEPENDENT REGIS (4)!REPORT OF INDEPENDENT REGIS (5)!REPORT OF INDEPENDENT REGIS (6)!REPORT OF INDEPENDENT REGIS (7)!REPORT OF INDEPENDENT REGIS (8)!REPORT OF INDEPENDENT REGIS (9)!REPORT OF INDEPENDENT REGI (10)!REPORT OF INDEPENDENT REGI (11)!REPORT OF INDEPENDENT REGI (12)!REPORT OF INDEPENDENT REGI (13)!REPORT OF INDEPENDENT REGI (14)!REPORT OF INDEPENDENT REGI (15)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/28/2011/'REPORT OF INDEPENDENT REGISTERED PUBLICDate: June 28, 2011 By:/s/ Teresa Fairbrook   Teresa Fairbrook  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan CommitteeDate: June 28, 2011 By:/s/ Chris PaulsenChris Paulsen0(Member of Pioneer Natural Resources USA, Inc.*"401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/4sg[OYs'y=PF0*8X> @ Root Entry FBook  %  !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~