<PAGE> PAGE 1
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000 C000000 0000831655
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001 A000000 MASSMUTUAL PARTICIPATION INVESTORS
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002 A000000 1295 STATE STREET
002 B000000 SPRINGFIELD
002 C000000 MA
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008 D020001 MA
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012 A000001 SHAREHOLDER FINANCIAL SERVICES, INC.
012 B000001 84-1817
012 C010001 DENVER
012 C020001 CO
012 C030001 80231
013 A000001 PRICEWATERHOUSECOOPERS LLP
013 B010001 SPRINGFIELD
013 B020001 MA
013 B030001 01101
015 A000001 THE CHASE MANHATTAN BANK, N.A.
015 B000001 C
<PAGE> PAGE 2
015 C010001 BROOKLYN
015 C020001 NY
015 C030001 11245
015 E010001 X
018 000000 Y
019 A000000 Y
019 B000000 35
019 C000000 MASSMUTUAL
020 A000001 DONALDSON, LUFKIN, & JENRETTE SECURITIES CORP
020 B000001 13-2741729
020 C000001 4
020 A000002 JONES & ASSOCIATES, INC.
020 B000002 95-3583143
020 C000002 4
020 A000003 DAIN RAUSCHER INCORPORATED
020 B000003 41-0212020
020 C000003 2
020 A000004 LAZARD FRERES & CO. LLC
020 B000004 13-5545100
020 C000004 2
020 A000005 ALLEN & CO. INCORPORATED
020 B000005 13-6176976
020 C000005 1
020 A000006 MERRILL LYNCH, PIERCE, FENNER & SMITH, INC.
020 B000006 13-5674085
020 C000006 1
020 A000007 HAMBRECHT & QUIST LLC
020 B000007 94-3220292
020 C000007 1
020 A000008 SCHRODER & CO. INC.
020 B000008 13-2697272
020 C000008 0
020 A000009 JANNEY MONTGOMERY SCOTT INC.
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022 C000002 44935
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022 A000003 LEHMAN BROTHERS INC.
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022 C000003 15581
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<PAGE> PAGE 3
022 A000004 MORGAN STANLEY & CO. INCORPORATED
022 B000004 13-2655998
022 C000004 4838
022 D000004 2226
022 A000005 BT ALEX. BROWN INCORPORATED
022 B000005 52-1319768
022 C000005 3465
022 D000005 1358
022 A000006 SALOMON SMITH BARNEY HOLDINGS INC.
022 C000006 2157
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022 A000007 DONALDSON LUFKIN, & JENRETTE SECURITIES CORP.
022 B000007 13-3224016
022 C000007 2078
022 D000007 1074
022 A000008 GRANTCHESTER SECURITIES INC.
022 B000008 13-3502273
022 C000008 335
022 D000008 2094
022 A000009 MORGAN (J.P.) SECURITIES INC.
022 B000009 13-3224016
022 C000009 1884
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022 A000010 CREDIT SUISSE FIRST BOSTON CORPORATION
022 B000010 13-5659485
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<PAGE> PAGE 4
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<PAGE> PAGE 7
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<PAGE> PAGE 8
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<PAGE> PAGE 9
084 B000000 0
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SIGNATURE CHARLES C. MCCOBB, JR.
TITLE VICE PRESIDENT & CFO
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MASSMUTUAL PARTICIPATION INVESTORS FOR THE SIX
MONTHS ENDED JUNE 30, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000831655
<NAME> MASSMUTUAL PARTICIPATION INVESTORS
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-START> JAN-01-1998
<PERIOD-END> JUN-30-1998
<INVESTMENTS-AT-COST> 126,512,071
<INVESTMENTS-AT-VALUE> 134,187,303
<RECEIVABLES> 2,796,917
<ASSETS-OTHER> 257,272
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 137,241,492
<PAYABLE-FOR-SECURITIES> 1,058,606
<SENIOR-LONG-TERM-DEBT> 22,500,000
<OTHER-ITEMS-LIABILITIES> 608,102
<TOTAL-LIABILITIES> 24,166,708
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 85,371,053
<SHARES-COMMON-STOCK> 9,257,181
<SHARES-COMMON-PRIOR> 9,216,665
<ACCUMULATED-NII-CURRENT> 2,632,773
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 3,599,315
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 7,675,232
<NET-ASSETS> 113,074,784
<DIVIDEND-INCOME> 118,956
<INTEREST-INCOME> 5,615,099
<OTHER-INCOME> 0
<EXPENSES-NET> 1,355,855
<NET-INVESTMENT-INCOME> 4,448,200
<REALIZED-GAINS-CURRENT> 3,603,354
<APPREC-INCREASE-CURRENT> 610,138
<NET-CHANGE-FROM-OPS> 8,661,692
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 2,218,130
<DISTRIBUTIONS-OF-GAINS> 0
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<NUMBER-OF-SHARES-SOLD> 0
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<AVERAGE-NET-ASSETS> 109,645,418
<PER-SHARE-NAV-BEGIN> 11.52
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<AVG-DEBT-PER-SHARE> 2.43
</TABLE>
