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<PAGE> PAGE 2
022 A000002 UBS AG
022 B000002 13-2932996
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022 B000004 13-2677075
022 C000004 2167137
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022 B000005 22-2347336
022 C000005 2115285
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022 B000006 13-2774727
022 C000006 1643626
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022 C000009 269000
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<PAGE> PAGE 3
025 A000004 BANK OF BOSTON
025 B000004 04-2472499
025 C000004 D
025 D000004 46996
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<PAGE> PAGE 4
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<PAGE> PAGE 5
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<PAGE> PAGE 6
070 K020000 N
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<PAGE> PAGE 7
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SIGNATURE MICHAEL S. PETRUCELLI
TITLE V.P AND ASST. TREAS.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0001038520
<NAME> DREYFUS INSTITUTIONAL PREFERRED MONEY MARKET FUND
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> MAR-31-1999
<PERIOD-END> SEP-30-1998
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<INVESTMENTS-AT-VALUE> 1669111
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<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1709370
<PAYABLE-FOR-SECURITIES> 25001
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<OTHER-ITEMS-LIABILITIES> 206
<TOTAL-LIABILITIES> 25207
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1684194
<SHARES-COMMON-STOCK> 1684194
<SHARES-COMMON-PRIOR> 1496629
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (31)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 1684163
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 41730
<OTHER-INCOME> 0
<EXPENSES-NET> 736
<NET-INVESTMENT-INCOME> 40994
<REALIZED-GAINS-CURRENT> (28)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 40966
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (40994)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3651509
<NUMBER-OF-SHARES-REDEEMED> (3504428)
<SHARES-REINVESTED> 40484
<NET-CHANGE-IN-ASSETS> 187537
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (3)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 736
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 736
<AVERAGE-NET-ASSETS> 1467428
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> .028
<PER-SHARE-GAIN-APPREC> .000
<PER-SHARE-DIVIDEND> (.028)
<PER-SHARE-DISTRIBUTIONS> .000
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> .001
<AVG-DEBT-OUTSTANDING> 000
<AVG-DEBT-PER-SHARE> .000
</TABLE>
