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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 7
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<PAGE> PAGE 8
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SIGNATURE ANNA RODRIQUES
TITLE MANAGER
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0001011008
<NAME> STATE STREET NAVIGATOR SECURITIES LENDING PRIME PORT.
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> DEC-31-1998
<PERIOD-END> DEC-31-1998
<INVESTMENTS-AT-COST> 6,742,508,111
<INVESTMENTS-AT-VALUE> 6,742,508,111
<RECEIVABLES> 50,858,790
<ASSETS-OTHER> 114,097
<OTHER-ITEMS-ASSETS> 0
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<TOTAL-LIABILITIES> 1,193,678
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</TABLE>
To the Board of Trustees and Shareholders of
State Street Navigator Securities Lending Trust
In planning and performing our audit of the
financial statements of State Street Navigator
Securities Lending Prime Portfolio (formerly
Navigator Securities Lending Prime Portfolio) (the
Fund), a series of State Street Navigator
Securities Lending Trust (formerly Navigator
Securities Lending Trust), for the year ended
December 31, 1998, 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 NSAR, and not
to provide assurance on the internal control.
The management of the Fund 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 control
activities. Generally, control activities that are
relevant to an audit pertain to the entitys
objective of preparing financial statements for
external purposes that are fairly presented in
conformity with generally accepted accounting
principles. Those control activities include the
safeguarding of assets against unauthorized
acquisition, use or disposition.
Because of inherent limitations in internal
control, errors or irregularities 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
the specific internal control does not reduce to a
relatively low level the risk that errors or
irregularities 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 internal control,
including control activities for safeguarding
securities, that we consider to be material
weaknesses as defined above as of December 31,
1998.
This report is intended solely for the information
and use of management and the Board of Trustees of
State Street Navigator Securities Lending Trust and
the Securities and Exchange Commission.
PricewaterhouseCoopers LLP
February 19, 1999
