<PAGE> PAGE 1
000 B000000 05/31/1999
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<PAGE> PAGE 2
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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 9
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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 17
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<PAGE> PAGE 18
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<PAGE> PAGE 19
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SIGNATURE MARK E. BRADLEY
TITLE ASSISTANT TREASURER
<TABLE> <S> <C>
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<CIK> 0000783740
<NAME> MFS SERIES TRUST X
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<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000783740
<NAME> MFS SERIES TRUST X
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<NAME> MFS INTERNATIONAL GROWTH AND INCOME FUND CLASS C
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<SENIOR-LONG-TERM-DEBT> 0
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<SENIOR-EQUITY> 0
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<SHARES-COMMON-STOCK> 143449
<SHARES-COMMON-PRIOR> 43821
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<NAME> MFS SERIES TRUST X
<SERIES>
<NUMBER> 024
<NAME> MFS INTERNATIONAL GROWTH AND INCOME FUND CLASS I
<MULTIPLIER> 1
<S> <C>
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<SHARES-COMMON-STOCK> 3270
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</TABLE>
Report of Independent Auditors
To the Trustees
MFS Series Trust X
In planning and performing our audits of the financial statements of MFS/Foreign
& Colonial Emerging Markets Equity Fund, MFS International Growth & Income Fund,
and MFS International Growth Fund ("the funds") three of the funds comprising
the MFS Series Trust X, for the year ended May 31, 1999, we considered its
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 internal control.
The management of the Funds 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 specific internal control components does not reduce to a relatively low
level the risk that errors 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 at May 31, 1999.
This report is intended solely for the information and use of the trustees and
management of MFS Series Trust X and the Securities and Exchange Commission and
is not intended to be and should not be used by anyone other than these
specified parties.
ERNST & YOUNG LLP
July 9, 1999
SUB-ITEM 77Q1 A copy of the Certification of Amendment to the Declaration of
Trust, Establishment and Designation of Series and Establishment and Designation
of Classes dated May 13, 1999 is contained in the Trust's Registration Statement
on Form N1A on behalf of the Funds, File Nos. 33-1657 and 811-4492, as filed
with the SEC via EDGAR on May 14, 1999. This document is to be incorporated
herein by reference.
