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<PAGE> PAGE 3
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<PAGE> PAGE 4
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<PAGE> PAGE 5
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<PAGE> PAGE 6
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<PAGE> PAGE 7
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<PAGE> PAGE 8
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<PAGE> PAGE 10
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<PAGE> PAGE 11
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<PAGE> PAGE 12
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<PAGE> PAGE 13
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<PAGE> PAGE 14
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<PAGE> PAGE 16
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<PAGE> PAGE 17
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<PAGE> PAGE 18
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<PAGE> PAGE 19
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<PAGE> PAGE 20
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<PAGE> PAGE 21
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SIGNATURE TRACIE PERSINGER
TITLE DIRECTOR
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<NUMBER> 011
<NAME> BARR ROSENBERG SERIES TRUST, U.S. SMALL CAPITALIZATION SERIES
<S> <C>
<PERIOD-TYPE> 12-MOS
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<PERIOD-END> MAR-31-1998
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<FN>
<F1>INSTITUTIONAL SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 012
<NAME> BARR ROSENBERG SERIES TRUST, U.S. SMALL CAPITALIZATION SERIES
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> MAR-31-1998
<PERIOD-END> MAR-31-1998
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<FN>
<F1>ADVISER SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 013
<NAME> BARR ROSENBERG SERIES TRUST, U.S. SMALL CAPITALIZATION SERIES
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> MAR-31-1998
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<NET-CHANGE-IN-ASSETS> 504364254
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<PER-SHARE-NII> (.02)<F1>
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<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>SELECT SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 021
<NAME> BARR ROSENBERG SERIES TRUST, JAPAN SERIES
<S> <C>
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<FISCAL-YEAR-END> MAR-31-1998
<PERIOD-END> MAR-31-1998
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<TOTAL-LIABILITIES> 27964
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<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 792129
<ACCUM-APPREC-OR-DEPREC> (150598)
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<NET-INVESTMENT-INCOME> (7910)
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<NET-CHANGE-IN-ASSETS> (106088)
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<PER-SHARE-NII> (.04)<F1>
<PER-SHARE-GAIN-APPREC> (1.44)<F1>
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<EXPENSE-RATIO> 1.50<F1>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>INSTITUTIONAL SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 022
<NAME> BARR ROSENBERG SERIES TRUST, JAPAN SERIES
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> MAR-31-1998
<PERIOD-END> MAR-31-1998
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<TOTAL-LIABILITIES> 27964
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1860548
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<SHARES-COMMON-PRIOR> 2048<F1>
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<ACCUMULATED-NET-GAINS> 0
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<ACCUM-APPREC-OR-DEPREC> (150598)
<NET-ASSETS> 915890
<DIVIDEND-INCOME> 8094
<INTEREST-INCOME> 0
<OTHER-INCOME> 0
<EXPENSES-NET> 16004
<NET-INVESTMENT-INCOME> (7910)
<REALIZED-GAINS-CURRENT> (345195)
<APPREC-INCREASE-CURRENT> 76999
<NET-CHANGE-FROM-OPS> (276106)
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<PER-SHARE-NII> (.04)<F1>
<PER-SHARE-GAIN-APPREC> (1.45)<F1>
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<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>SELECT SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 031
<NAME> BARR ROSENBERG SERIES TRUST, INTERNATIONAL SMALL CAPITALIZATION SERIES
<S> <C>
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<FISCAL-YEAR-END> MAR-31-1998
<PERIOD-END> MAR-31-1998
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<NUMBER-OF-SHARES-REDEEMED> 865143<F1>
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<PER-SHARE-NAV-BEGIN> 10.13<F1>
<PER-SHARE-NII> .08<F1>
<PER-SHARE-GAIN-APPREC> .14<F1>
<PER-SHARE-DIVIDEND> .05<F1>
<PER-SHARE-DISTRIBUTIONS> .20<F1>
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<FN>
<F1>INSTITUTIONAL SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<SERIES>
<NUMBER> 032
<NAME> BARR ROSENBERG SERIES TRUST, INTERNATIONAL SMALL CAPITALIZATION SERIES
<S> <C>
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<FISCAL-YEAR-END> MAR-31-1998
<PERIOD-END> MAR-31-1998
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<GROSS-EXPENSE> 649563
<AVERAGE-NET-ASSETS> 491325<F1>
<PER-SHARE-NAV-BEGIN> 10.13<F1>
<PER-SHARE-NII> .06<F1>
<PER-SHARE-GAIN-APPREC> .14<F1>
<PER-SHARE-DIVIDEND> .04<F1>
<PER-SHARE-DISTRIBUTIONS> .20<F1>
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<PER-SHARE-NAV-END> 10.09<F1>
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<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>SELECT SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
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<CIK> 0000832545
<NAME> BARR ROSENBERG SERIES TRUST
<SERIES>
<NUMBER> 041
<NAME> BARR ROSENBERG SERIES TRUST, MARKET NEUTRAL FUND
<S> <C>
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<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 700708
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1256513
<AVERAGE-NET-ASSETS> 110627765<F1>
<PER-SHARE-NAV-BEGIN> 10.00<F1>
<PER-SHARE-NII> .10<F1>
<PER-SHARE-GAIN-APPREC> (.13)<F1>
<PER-SHARE-DIVIDEND> 0<F1>
<PER-SHARE-DISTRIBUTIONS> 0<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 9.97<F1>
<EXPENSE-RATIO> 2.75<F1>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>INSTITUTIONAL SHARES
</FN>
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000832545
<NAME> BARR ROSENBERG SERIES TRUST
<SERIES>
<NUMBER> 042
<NAME> BARR ROSENBERG SERIES TRUST, MARKET NEUTRAL FUND
<S> <C>
<PERIOD-TYPE> 4-MOS
<FISCAL-YEAR-END> MAR-31-1998
<PERIOD-START> DEC-18-1997
<PERIOD-END> MAR-31-1998
<INVESTMENTS-AT-COST> 190284882
<INVESTMENTS-AT-VALUE> 207843567
<RECEIVABLES> 11986119
<ASSETS-OTHER> 30750
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 404442932
<PAYABLE-FOR-SECURITIES> 13341080
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 187799069
<TOTAL-LIABILITIES> 201140149
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 203547941
<SHARES-COMMON-STOCK> 3537423<F1>
<SHARES-COMMON-PRIOR> 0<F1>
<ACCUMULATED-NII-CURRENT> 1201284
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 2113934
<ACCUM-APPREC-OR-DEPREC> 667492
<NET-ASSETS> 203302783
<DIVIDEND-INCOME> 322963
<INTEREST-INCOME> 1915589
<OTHER-INCOME> 0
<EXPENSES-NET> 1043550
<NET-INVESTMENT-INCOME> 1195002
<REALIZED-GAINS-CURRENT> (2109737)
<APPREC-INCREASE-CURRENT> 667492
<NET-CHANGE-FROM-OPS> (247243)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0<F1>
<DISTRIBUTIONS-OF-GAINS> 0<F1>
<DISTRIBUTIONS-OTHER> 0<F1>
<NUMBER-OF-SHARES-SOLD> 3701007<F1>
<NUMBER-OF-SHARES-REDEEMED> 163584<F1>
<SHARES-REINVESTED> 0<F1>
<NET-CHANGE-IN-ASSETS> 203302783
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 700708
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1256513
<AVERAGE-NET-ASSETS> 17538964<F1>
<PER-SHARE-NAV-BEGIN> 10.00<F1>
<PER-SHARE-NII> .08<F1>
<PER-SHARE-GAIN-APPREC> (.12)<F1>
<PER-SHARE-DIVIDEND> 0<F1>
<PER-SHARE-DISTRIBUTIONS> 0<F1>
<RETURNS-OF-CAPITAL> 0<F1>
<PER-SHARE-NAV-END> 9.96<F1>
<EXPENSE-RATIO> 3.34<F1>
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
<FN>
<F1>INVESTOR SHARES
</FN>
</TABLE>
May 13, 1998
To the Shareholders and Board of Trustees of
Barr Rosenberg Series Trust
In planning and performing our audits of the
financial statements of the U.S. Small
Capitalization Series, International Small
Capitalization Series, Japan Series, and
Market Neutral Fund, each a series of the
Barr Rosenberg Series Trust (the "Trust") for
the periods ended March 31, 1998, we considered
their internal control, including control activities
for safeguarding securities, in order to determine
our auditing procedures for the purpose of expressing
our opinion on the financial statements and to comply
with the requirements of Form N-SAR, not to provide
assurance on internal control.
The management of the Trust is responsible for
establishing and maintaining internal control.
In fulfilling this responsibility, estimates and
judgments by management are required to assess
the expected benefits and related costs of controls.
Generally, controls that are relevant to an audit
pertain to the entity's objective of preparing financial
statements for external purposes that are fairly
presented in conformity with generally accepted
accounting principles. Those controls include the
safeguarding of assets against unauthorized acquisition,
use or disposition.
Because of inherent limitations in internal control,
errors or fraud may occur and not be detected. Also,
projection of any evaluation of internal control to
future periods is subject to the risk that it may become
inadequate because of changes in conditions or that
the effectiveness of the design and operation may deteriorate.
Our consideration of internal control would not necessarily
disclose all matters in internal control that might be
material weaknesses under standards established by
the American Institute of Certified Public Accountants.
A material weakness is a condition in which the design
or operation of one or more of the internal control
components does not reduce to a relatively low level
the risk that misstatements caused by error or fraud in
amounts that would be material in relation to the
financial statements being audited may occur and not
be detected within a timely period by employees in
the normal course of performing their assigned functions.
However, we noted no matters involving internal control
and its operation, including controls for safeguarding
securities, that we consider to be material weaknesses
as defined above as of March 31, 1998.
This report is intended solely for the information and use
of management and the Board of Trustees of Barr
Rosenberg Series Trust and the Securities and Exchange
Commission.
