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<PAGE> PAGE 3
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<PAGE> PAGE 7
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<PAGE> PAGE 11
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<PAGE> PAGE 13
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SIGNATURE ELLEN MOYNIHAN
TITLE ASSISTANT TREASURER
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<SERIES>
<NUMBER> 022
<NAME> MFS MUNICIPAL HIGH INCOME FUND CLASS B
<MULTIPLIER> 1
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-2000
<PERIOD-START> FEB-01-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 1497932544
<INVESTMENTS-AT-VALUE> 1556591965
<RECEIVABLES> 25952971
<ASSETS-OTHER> 18346
<OTHER-ITEMS-ASSETS> 21020
<TOTAL-ASSETS> 1582584302
<PAYABLE-FOR-SECURITIES> 16965725
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7184999
<TOTAL-LIABILITIES> 24150724
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1655857142
<SHARES-COMMON-STOCK> 43913546
<SHARES-COMMON-PRIOR> 40172395
<ACCUMULATED-NII-CURRENT> 864000
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> (157013757)
<ACCUM-APPREC-OR-DEPREC> 58726193
<NET-ASSETS> 1558433578
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 50711211
<OTHER-INCOME> 0
<EXPENSES-NET> (7528266)
<NET-INVESTMENT-INCOME> 43182945
<REALIZED-GAINS-CURRENT> 16738880
<APPREC-INCREASE-CURRENT> (75944367)
<NET-CHANGE-FROM-OPS> (16022542)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (9637149)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 6342261
<NUMBER-OF-SHARES-REDEEMED> (2969190)
<SHARES-REINVESTED> 368080
<NET-CHANGE-IN-ASSETS> 24020528
<ACCUMULATED-NII-PRIOR> 2468242
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> (173752637)
<GROSS-ADVISORY-FEES> 4624469
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8043202
<AVERAGE-NET-ASSETS> 1559212975
<PER-SHARE-NAV-BEGIN> 9.04
<PER-SHARE-NII> 0.22
<PER-SHARE-GAIN-APPREC> (0.34)
<PER-SHARE-DIVIDEND> (0.23)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.69
<EXPENSE-RATIO> 1.61
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225604
<NAME> MFS SERIES TRUST III
<SERIES>
<NUMBER> 023
<NAME> MFS MUNICIPAL HIGH INCOME FUND CLASS C
<MULTIPLIER> 1
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JAN-31-2000
<PERIOD-START> FEB-01-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 1497932544
<INVESTMENTS-AT-VALUE> 1556591965
<RECEIVABLES> 25952971
<ASSETS-OTHER> 18346
<OTHER-ITEMS-ASSETS> 21020
<TOTAL-ASSETS> 1582584302
<PAYABLE-FOR-SECURITIES> 16965725
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7184999
<TOTAL-LIABILITIES> 24150724
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1655857142
<SHARES-COMMON-STOCK> 1661497
<SHARES-COMMON-PRIOR> 317766
<ACCUMULATED-NII-CURRENT> 864000
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> (157013757)
<ACCUM-APPREC-OR-DEPREC> 58726193
<NET-ASSETS> 1558433578
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 50711211
<OTHER-INCOME> 0
<EXPENSES-NET> (7528266)
<NET-INVESTMENT-INCOME> 43182945
<REALIZED-GAINS-CURRENT> 16738880
<APPREC-INCREASE-CURRENT> (75944367)
<NET-CHANGE-FROM-OPS> (16022542)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (212727)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1391632
<NUMBER-OF-SHARES-REDEEMED> (58804)
<SHARES-REINVESTED> 10903
<NET-CHANGE-IN-ASSETS> 24020528
<ACCUMULATED-NII-PRIOR> 2468242
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> (173752637)
<GROSS-ADVISORY-FEES> 4624469
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8043202
<AVERAGE-NET-ASSETS> 1559212975
<PER-SHARE-NAV-BEGIN> 9.04
<PER-SHARE-NII> 0.21
<PER-SHARE-GAIN-APPREC> (0.34)
<PER-SHARE-DIVIDEND> (0.22)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.69
<EXPENSE-RATIO> 1.79
</TABLE>
#6616/33226
SUB-ITEM 77-H
MFS SERIES TRUST III ON BEHALF OF:
MFS HIGH YIELD OPPORTUNITIES FUND ("HYO")
As of July 31, 1999, the entities beneficially owning 25% or more of
HYO's voting securities, thereby becoming controlling entities of such Series,
are those entities listed as follows:
<TABLE>
<CAPTION> % O
SHARES
SERIES OWNER AND ADDRESS OWNED
<S> <C>
MFS High Yield Opportunities Fund None
</TABLE>
<PAGE>
As of July 31, 1999, entities no longer beneficially owning 25% or more
of HYO's voting securities, thereby ceasing to be controlling entities of such
Series, are those entities listed as follows:
<TABLE>
<CAPTION> SERIES OWNER AND ADDRESS
<S> <C>
MFS High Yield Opportunities Fund MFS Fund Distributors, Inc.
Class A Shares C/o Massachusetts Financial Services
Attn: Thomas B. Hastings
500 Boylston Street - 15th Floor
Boston, MA 02116
Dean Witter Reynolds
Class B Shares Custodian for Beatrice Russell
IRA Rollover dated 10/17/89
4 Maple Hill Road
Lebanon, NH 03766-2722
NFSC FEBO #041-081400
Class C Shares George An Nikoras
5 Falls Grove Road
Nashua, NH
</TABLE>
