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<PAGE> PAGE 2
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<PAGE> PAGE 7
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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 15
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<PAGE> PAGE 16
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<PAGE> PAGE 18
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<PAGE> PAGE 19
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SIGNATURE ELLEN MOYNIHAN
TITLE ASSISTANT TREASURER
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<TABLE> <S> <C>
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<CIK> 0000225604
<NAME> MFS SERIES TRUST III
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<NET-INVESTMENT-INCOME> 124791134
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<DISTRIBUTIONS-OF-INCOME> (9587399)
<DISTRIBUTIONS-OF-GAINS> 0
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<NUMBER-OF-SHARES-SOLD> 18812025
<NUMBER-OF-SHARES-REDEEMED> (15975020)
<SHARES-REINVESTED> 1032152
<NET-CHANGE-IN-ASSETS> 20921047
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> (3855509)
<OVERDIST-NET-GAINS-PRIOR> (166139215)
<GROSS-ADVISORY-FEES> 6463845
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<GROSS-EXPENSE> 18307105
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<PER-SHARE-NAV-BEGIN> 5.22
<PER-SHARE-NII> 0.43
<PER-SHARE-GAIN-APPREC> (0.24)
<PER-SHARE-DIVIDEND> (0.44)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 4.97
<EXPENSE-RATIO> 1.68
</TABLE>
<TABLE> <S> <C>
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<CIK> 0000225604
<NAME> MFS SERIES TRUST III
<SERIES>
<NUMBER> 014
<NAME> MFS HIGH INCOME FUND CLASS I
<MULTIPLIER> 1
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<SHARES-COMMON-STOCK> 3621703
<SHARES-COMMON-PRIOR> 1664289
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<DISTRIBUTIONS-OF-INCOME> (1331385)
<DISTRIBUTIONS-OF-GAINS> 0
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<NUMBER-OF-SHARES-SOLD> 2196852
<NUMBER-OF-SHARES-REDEEMED> (428729)
<SHARES-REINVESTED> 189291
<NET-CHANGE-IN-ASSETS> 20921047
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> (3855509)
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<PER-SHARE-NAV-BEGIN> 5.21
<PER-SHARE-NII> 0.48
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<PER-SHARE-DIVIDEND> (0.50)
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</TABLE>
INDEPENDENT AUDITORS' REPORT
To the Trustees and Shareholders of MFS Series Trust III:
In planning and performing our audits of the financial statements of MFS High
Income Fund and MFS High Yield Opportunities Fund (each a series of MFS Series
Trust III) (the "Trust") for the year ended January 31, 2000 (on which we have
issued our reports dated March 9, 2000), 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, and not
to provide assurance on the Trust's 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 any internal control, misstatements due to
error 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 the internal
control may become inadequate because of changes in conditions or that the
degree of compliance with policies or procedures deteriorates.
Our consideration of the Trust's 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 the
Trust's internal control and its operation, including controls for safeguarding
securities that we consider to be material weaknesses as defined above as of
January 31, 2000.
This report is intended solely for the information and use of management, the
Board of Trustees and Shareholders of MFS Series Trust III, and the Securities
and Exchange Commission and is not intended to be and should not be used by
anyone other than these specified parties.
March 9, 2000
Exhibit 77D
The MFS High Yield Opportunities Fund, a series of MFS Series Trust III changed
the percentage of net assets that the Fund may invest in Foreign Securities
(including Emerging Markets) from 25% to 50% as described in the statement of
additional information contained in Post-Effective Amendment No. 28 to the
Registration Statement (File Nos. 2-60491 and 811-2794) filed with Securities
and Exchange Comission via EDGAR on March 31, 1999. Such description is
incorporated herein by reference.
