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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
 Washington, DC 20549
 
 FORM 11-K
  þ

    ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 For the fiscal year ended December 31, 2010
 OR
 o

    TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 For the transition period from  to
 Commission file number 001-14141
 L-3 COMMUNICATIONS
MASTER SAVINGS PLAN
 (Full title of the plan and the address of the plan,  if different from that of the issuer named below)
 L-3 COMMUNICATIONS HOLDINGS, INC.




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
Index to Financial Statements and Supplemental Schedule
 PageReport of Independent Registered Public Accounting Firm
    
    
    2Financial Statements:Statements of Net Assets Available for Benefits at December 31, 2010 and 2009
    
    
    3Statement of Changes in Net Assets Available for Benefits for the year ended December 31, 2010
    
    
    4Notes to Financial Statements
    
    
    5-14Supplemental Schedule:Schedule H, line 4i*  Schedule of Assets (Held at End of Year)
    
    
    15EX-23
  
 *
    
    Refers to item number in Form 5500 (Annual Return/Report of Employee Benefit Plan) filed
with the Department of Labor for the plan year ended December 31, 2010.Other schedules required by 29 CFR 2520.103-10 of the Department of Labors Rules and
Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of
1974 have been omitted as the conditions under which they are required are not present.




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Report of Independent Registered Public Accounting Firm
 
   /s/ PricewaterhouseCoopers LLPPricewaterhouseCoopers LLPNew York, New YorkJune 21, 2011




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS
AS OF DECEMBER 31, 2010 AND 2009
(in thousands)
 2010
    
    
    2009Assets:Investment in Master Trust, at fair value
    
    $
    3,469,666
    
    
    $
    3,169,200Receivables:Employer contribution
    
    
    20,019
    
    
    
    17,592Participant contributions
    
    
    6,642
    
    
    
    7,231Notes receivable from participants
    
    
    78,684
    
    
    
    69,903Total receivables
    
    
    105,345
    
    
    
    94,726Total assets
    
    
    3,575,011
    
    
    
    3,263,926Adjustment from fair value to contract
value for interest in collective trust
relating to fully benefit-responsive
investment contracts
    
    
    (6,092
    )
    
    
    7,614Net assets available for benefits
    
    $
    3,568,919
    
    
    $
    3,271,540
  3




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS
FOR THE YEAR ENDED DECEMBER 31, 2010
(in thousands)
 Additions:Contributions:Employer
    
    $
    148,541Participant
    
    
    283,766Rollover
    
    
    20,782Total contributions
    
    
    453,089Plan interest in the Master Trust net investment income
    
    
    150,069Interest income on notes receivable from participants
    
    
    4,006Total additions
    
    
    607,164Deductions:Benefit payments
    
    
    341,107Administrative expenses
    
    
    901Total deductions
    
    
    342,008Net increase prior to plan mergers
    
    
    265,156Transfers in from other plans (Note 1)
    
    
    32,223Net increase
    
    
    297,379Net assets available for benefits, beginning of period
    
    
    3,271,540Net assets available for benefits, end of period
    
    $
    3,568,919
  4




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
 
 NOTES TO FINANCIAL STATEMENTS
 1. Plan Description
 General
   Transfers from Other Plans
  Participant Contributions
    Participant Accounts
  Master Trust Investments
  5




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
 2. Summary of Significant Accounting Policies
 Investment in Master Trust
   Valuation of Investments
    Basis of Accounting
     6




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
 New Accounting Standard Implemented
  Investment Transactions and Investment Income
  Forfeitures
  Benefit Payments
  Plan Expenses
  Risks and Uncertainties
  3. Company Contributions and Vesting Provisions
  7




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
     8




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
 4. Master Trust
  Master Trust
    
    
    Plans PortionFund
    
    2010
    
    
    2009
    
    
    2010
    
    
    2009(in thousands)Investments at Fair Value as Determined by
Quoted Market Price:American Funds Growth Fund of America  Class R6*
    
    $
    161,146
    
    
    $
    148,945
    
    
    $
    160,523
    
    
    $
    148,476BlackRock High Yield Bond Portfolio. BlackRock
Shares *
    
    
    54,155
    
    
    
    18,860
    
    
    
    53,719
    
    
    
    18,764Calamos Growth Fund  Institutional Class*
    
    
    164,913
    
    
    
    136,499
    
    
    
    163,781
    
    
    
    135,599Davis New York Venture Fund, Inc. Class Y*
    
    
    107,958
    
    
    
    98,246
    
    
    
    107,591
    
    
    
    97,935Dodge & Cox Income Fund*
    
    
    160,663
    
    
    
    135,958
    
    
    
    159,501
    
    
    
    135,149Dodge & Cox Stock Fund*
    
    
    206,320
    
    
    
    183,711
    
    
    
    204,754
    
    
    
    182,286Fidelity Balanced Fund Class K*
    
    
    23,217
    
    
    
    
    
    
    
    23,139
    
    
    
    Fidelity Balanced Fund*
    
    
    
    
    
    
    13,439
    
    
    
    
    
    
    
    13,422Fidelity Diversified International Fund Class K*
    
    
    215,256
    
    
    
    
    
    
    
    214,029
    
    
    
    Fidelity Diversified International Fund*
    
    
    
    
    
    
    205,243
    
    
    
    
    
    
    
    204,034Fidelity Freedom K 2000 Fund*
    
    
    14,029
    
    
    
    
    
    
    
    13,988
    
    
    
    Fidelity Freedom K 2005 Fund*
    
    
    1,079
    
    
    
    
    
    
    
    1,073
    
    
    
    Fidelity Freedom K 2010 Fund*
    
    
    94,681
    
    
    
    
    
    
    
    94,435
    
    
    
    Fidelity Freedom K 2015 Fund*
    
    
    19,510
    
    
    
    
    
    
    
    19,466
    
    
    
    Fidelity Freedom K 2020 Fund*
    
    
    153,798
    
    
    
    
    
    
    
    152,885
    
    
    
    Fidelity Freedom K 2025 Fund*
    
    
    20,885
    
    
    
    
    
    
    
    20,821
    
    
    
    Fidelity Freedom K 2030 Fund*
    
    
    105,646
    
    
    
    
    
    
    
    104,472
    
    
    
    Fidelity Freedom K 2035 Fund*
    
    
    10,956
    
    
    
    
    
    
    
    10,844
    
    
    
    Fidelity Freedom K 2040 Fund*
    
    
    23,562
    
    
    
    
    
    
    
    23,437
    
    
    
    Fidelity Freedom K 2045 Fund*
    
    
    10,079
    
    
    
    
    
    
    
    10,078
    
    
    
    Fidelity Freedom K 2050 Fund*
    
    
    15,074
    
    
    
    
    
    
    
    15,006
    
    
    
    Fidelity Freedom 2000 Fund*
    
    
    
    
    
    
    13,499
    
    
    
    
    
    
    
    13,465Fidelity Freedom 2005 Fund*
    
    
    
    
    
    
    784
    
    
    
    
    
    
    
    778Fidelity Freedom 2010 Fund*
    
    
    
    
    
    
    91,461
    
    
    
    
    
    
    
    91,252Fidelity Freedom 2015 Fund*
    
    
    
    
    
    
    9,609
    
    
    
    
    
    
    
    9,574Fidelity Freedom 2020 Fund*
    
    
    
    
    
    
    130,926
    
    
    
    
    
    
    
    130,012Fidelity Freedom 2025 Fund*
    
    
    
    
    
    
    8,623
    
    
    
    
    
    
    
    8,568Fidelity Freedom 2030 Fund*
    
    
    
    
    
    
    82,164
    
    
    
    
    
    
    
    81,443Fidelity Freedom 2035 Fund*
    
    
    
    
    
    
    4,491
    
    
    
    
    
    
    
    4,470Fidelity Freedom 2040 Fund*
    
    
    
    
    
    
    15,258
    
    
    
    
    
    
    
    15,169Fidelity Freedom 2045 Fund*
    
    
    
    
    
    
    3,794
    
    
    
    
    
    
    
    3,793Fidelity Freedom 2050 Fund*
    
    
    
    
    
    
    8,854
    
    
    
    
    
    
    
    8,813Fidelity Ginnie Mae Fund*
    
    
    112,228
    
    
    
    107,576
    
    
    
    111,732
    
    
    
    106,894Fidelity Magellan Fund Class K*
    
    
    157,418
    
    
    
    
    
    
    
    156,391
    
    
    
    Fidelity Magellan Fund*
    
    
    
    
    
    
    145,240
    
    
    
    
    
    
    
    144,356Spartan U.S. Equity Index Fund  Advantage Class*
    
    
    139,272
    
    
    
    119,763
    
    
    
    138,549
    
    
    
    119,243T. Rowe Price Small-Cap Stock Fund*
    
    
    214,631
    
    
    
    146,418
    
    
    
    213,694
    
    
    
    148,805Victory Special Value Fund  Class I*
    
    
    18,826
    
    
    
    9,882
    
    
    
    18,730
    
    
    
    9,824Vanguard Inflation  Protected Securities Fund
Investor Shares *
    
    
    10,266
    
    
    
    
    
    
    
    10,195
    
    
    
    $
    2,215,568
    
    
    $
    1,839,243
    
    
    $
    2,202,833
    
    
    $
    1,829,124Investments at Estimated Fair ValueL-3 Stock Fund
    
    
    656,530
    
    
    
    741,567
    
    
    
    649,908
    
    
    
    734,049Fidelity Managed Income Portfolio II  Class 3**
    
    
    620,050
    
    
    
    608,781
    
    
    
    616,925
    
    
    
    606,0271,276,580
    
    
    
    1,350,348
    
    
    
    1,266,833
    
    
    
    1,340,076$
    3,492,148
    
    
    $
    3,189,591
    
    
    $
    3,469,666
    
    
    $
    3,169,200
 
 *
    
    Mutual Fund**
    
    Common/Collective Trust Fund 9




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
  Master Trust
    
    
    Plans Portion(in thousands)Investment Income:Net appreciation in investments
    
    $
    71,335
    
    
    $
    71,678Interest and dividend income
    
    
    78,876
    
    
    
    78,391Net investment income
    
    $
    150,211
    
    
    $
    150,069
   5. Fair Value Measurements
  Level 1:
    
    Quoted market prices available in active markets for identical
assets or liabilities as of the reporting date. The Plans Level
1 assets include mutual funds, whose fair values are derived from
quoted market prices.Level 2:
    
    Pricing inputs, other than quoted prices in active markets
included in Level 1, which are either directly or indirectly
observable. The Plans Level 2 assets include the L-3 Stock Fund
and the MIP Fund. See Note 6 for the valuation techniques used
by FMTC to measure the fair value of the MIP Funds investment in
fully benefit-responsive investment contracts.Level 3:
    
    Pricing inputs that are generally unobservable and not
corroborated by market data. The Plan does not have any Level 3
investments.
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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
  Fair Value Measurements Using Input Type2010
    
    
    2009Level 1
    
    
    Level 2
    
    
    Level 3
    
    
    Total
    
    
    Level 1
    
    
    Level 2
    
    
    Level 3
    
    
    Total(in thousands)Mutual funds
    
    $
    2,202,833
    
    
    $
    
    
    
    $
    
    
    
    $
    2,202,833
    
    
    $
    1,829,124
    
    
    $
    
    
    
    $
    
    
    
    $
    1,829,124L-3 Stock Fund
    
    
    
    
    
    
    649,908
    
    
    
    
    
    
    
    649,908
    
    
    
    
    
    
    
    734,049
    
    
    
    
    
    
    
    734,049Common/collective
trust fund
    
    
    
    
    
    
    616,925
    
    
    
    
    
    
    
    616,925
    
    
    
    
    
    
    
    606,027
    
    
    
    
    
    
    
    606,027Total
investments
measured at fair
value
    
    $
    2,202,833
    
    
    $
    1,266,833
    
    
    $
    
    
    
    $
    3,469,666
    
    
    $
    1,829,124
    
    
    $
    1,340,076
    
    
    $
    
    
    
    $
    3,169,200
 6. Benefit-Responsive Investment Contracts
  Wrap Contracts.
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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
     7. Benefit Payments
 1 2
 1 2 1 2 1 2
 8. Loans
   12




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
 9. Accounting Standards Issued and Not Yet Implemented
  10. Tax Status
   11. Related-Party Transactions
   12. Termination Priorities
  13. Subsequent Event
  13




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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
NOTES TO FINANCIAL STATEMENTS  Continued
 14. Reconciliation of Financial Statements to Form 5500
  December 31,2010
    
    
    2009(in thousands)Net assets available for benefits per the financial statements
    
    $
    3,568,919
    
    
    $
    3,271,540Less: Adjustment from fair value to contract value for fully
benefit-responsive investment contracts
    
    
    6,092
    
    
    
    (7,614
    )Net assets available for benefits per the Form 5500
    
    $
    3,575,011
    
    
    $
    3,263,926
 December 31,2010(in thousands)Total investment income per the financial statements
    
    $
    150,069Add: Adjustment from fair value to contract value for fully benefit-responsive investment
contracts
    
    
    13,706Total investment income per the Form 5500
    
    $
    163,775
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L-3 COMMUNICATIONS MASTER SAVINGS PLAN
SCHEDULE H, LINE 4i  SCHEDULE OF ASSETS (HELD AT END OF YEAR)
DECEMBER 31, 2010
 (in thousands)
 Description of Investment
    
    Cost
    
    
    Current ValueParticipant loans*
    
    
    
    
    
    $
    78,530Total
    
    
    
    
    
    $
    78,530
 
 *
    
    Consists of participant loans of with interest rates from 4.25% to 9.25% maturing through
December 2040. 15




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L-3 Communications Master Savings Plan
RegistrantDate: June 21, 2011
    /s/ Ralph G. DAmbrosioName:
    Ralph G. DAmbrosioTitle:
    Authorized Signatory,
L-3 Benefit Plan Committee