<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000878089
<NAME> PAINEWEBBER MANAGED ASSETS TRUST
<SERIES>
<NUMBER> 1
<NAME> MID CAP FUND CLASS Y
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> AUG-31-2000
<PERIOD-START> SEP-01-1999
<PERIOD-END> AUG-31-2000
<INVESTMENTS-AT-COST> 443
<INVESTMENTS-AT-VALUE> 749
<RECEIVABLES> 1
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 90
<TOTAL-ASSETS> 840
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 93
<TOTAL-LIABILITIES> 93
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 356
<SHARES-COMMON-STOCK> 746
<SHARES-COMMON-PRIOR> 27
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 84
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 306
<NET-ASSETS> 746
<DIVIDEND-INCOME> 2
<INTEREST-INCOME> 2
<OTHER-INCOME> 0
<EXPENSES-NET> 11
<NET-INVESTMENT-INCOME> 7
<REALIZED-GAINS-CURRENT> 93
<APPREC-INCREASE-CURRENT> 215
<NET-CHANGE-FROM-OPS> 301
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (33)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 33
<NUMBER-OF-SHARES-REDEEMED> 19
<SHARES-REINVESTED> 3
<NET-CHANGE-IN-ASSETS> 209
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 23
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 6
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8
<AVERAGE-NET-ASSETS> 538
<PER-SHARE-NAV-BEGIN> 10.70
<PER-SHARE-NII> (0.07)
<PER-SHARE-GAIN-APPREC> 7.22
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.93)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 16.92
<EXPENSE-RATIO> 1.23
</TABLE>
