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<PAGE> PAGE 2
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<PAGE> PAGE 3
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SIGNATURE CHARLES C. MCCOBB
TITLE VICE PRESIDENT & CFO
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MASSMUTUAL CORPORATE INVESTORS FOR THE YEAR
ENDED DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO
SUCH FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000275694
<NAME> MASSMUTUAL CORPORATE INVESTORS
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 240,864,750
<INVESTMENTS-AT-VALUE> 225,594,468
<RECEIVABLES> 3,885,385
<ASSETS-OTHER> 209,184
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 229,689,037
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 20,000,000
<OTHER-ITEMS-LIABILITIES> 20,728,277
<TOTAL-LIABILITIES> 40,728,277
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 104,651,714
<SHARES-COMMON-STOCK> 8,587,495
<SHARES-COMMON-PRIOR> 8,587,495
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<OVERDISTRIBUTION-GAINS> 0
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<NET-ASSETS> 188,960,760
<DIVIDEND-INCOME> 785,458
<INTEREST-INCOME> 18,344,363
<OTHER-INCOME> 0
<EXPENSES-NET> 3,694,138
<NET-INVESTMENT-INCOME> 15,435,683
<REALIZED-GAINS-CURRENT> 22,291,364
<APPREC-INCREASE-CURRENT> (30,341,829)
<NET-CHANGE-FROM-OPS> 7,385,218
<EQUALIZATION> 0
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<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> (16,058,643)
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<ACCUMULATED-GAINS-PRIOR> 84,627,528
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 2,013,708
<INTEREST-EXPENSE> 1,066,000
<GROSS-EXPENSE> 3,694,138
<AVERAGE-NET-ASSETS> 202,462,447
<PER-SHARE-NAV-BEGIN> 23.87
<PER-SHARE-NII> 1.80
<PER-SHARE-GAIN-APPREC> (0.94)
<PER-SHARE-DIVIDEND> 1.73
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</TABLE>
EXHIBIT INDEX TO FORM N-SAR
OF MASSMUTUAL CORPORATE INVESTORS
FOR YEAR ENDED DECEMBER 31, 1999
EXHIBIT NO. DESCRIPTION
77B Accountant's Report on Internal Control
77K Changes in Registrant's certifying accountant
77Q1(f) Letter from independent accountant furnished pursuant to Sub-
Item 77K
77Q2 Information Called for by the Instructions to Sub-Item 77Q2
For Period Ended 12/31/99
File No. 811-2183
77B Accountant's Report on Internal Control
INDEPENDENT AUDITORS' REPORT
The Board of Trustees,
MassMutual Corporate Investors:
In planning and performing our audit of the financial statements of
MassMutual Corporate Investors (the "Trust") for the year ended December 31,
1999 (on which we have issued our report dated February 18, 2000), 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 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, projections of any
evaluation of internal control to future periods are 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 may deteriorate.
Our consideration of the Trust's internal control would not necessarily
disclose all matters in the 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 December 31, 1999.
This report is intended solely for the information and use of management, the
Board of Trustees of the Trust, and the Securities and Exchange Commission
and is not intended to be and should not be used by anyone other than these
specified parties.
/s/ Deloitte & Touche LLP
February 18, 2000
For Period Ended 12/31/99
File No. 811-2183
77K Changes in Registrant's certifying accountant
PricewaterhouseCoopers LLP ("PwC") resigned as auditors of Registrant,
effective September 7, 1999. PwC's report on the financial statements for
the fiscal years 1997 and 1998 did not contain an adverse opinion or a
disclaimer of opinion, and was not qualified or modified as to uncertainty,
audit scope or accounting principles.
Registrant's Audit Committee recommended engaging Deloitte & Touche LLP as
the principal accountant to audit the Registrant's financial statements for
fiscal year 1999. A majority of Registrant's Board of Trustees, including a
majority of the independent Trustees, approved the appointment of Deloitte &
Touche LLP as Registrant's independent auditors for Registrant's fiscal 1999
audit at a meeting of Registrant's Board of Trustees on October 22, 1999
subject to the right of Registrant, by a majority vote of the shareholders at
any meeting called for that purpose, to terminate any appointment without
penalty and further subject to Deloitte & Touche's continued independence.
For fiscal years 1997 and 1998, and during the period prior to PwC's
resignation, Registrant and PwC have not had any disagreements on any matter
of accounting principles or practices, financial statement disclosures, or
auditing scope or procedure, that either (1) have not been resolved to PwC's
satisfaction and (2) or, if not resolved to PwC's satisfaction, would have
caused it to make a reference to the subject matter of the disagreement in
connection with its report.
Registrant discloses that no "reportable events" as defined in Item 304(a)(v)
existed for fiscal years 1997 and 1998 and during the period prior to PwC's
resignation, specifically:
PwC did not advise Registrant that the internal controls necessary for
Registrant to develop financial statements do not exist;
PwC did not advise Registrant that it can no longer rely on management's
representations, or that it was unwilling to be associated with the
financial statements prepared by management;
PwC did not advise Registrant of the need to expand significantly the
scope of its audit;
PwC did not advise Registrant that information had come to its attention
that would materially impact the fairness or reliability of either (i) a
previously issued audit report of the underlying financial statements, or
(ii) the financial statements issued or to be issued covering fiscal year
1999.
Registrant has not consulted Deloitte & Touche LLP on any accounting matters
prior to its engagement.
Pursuant to the requirements of Item 304(a)(3), Registrant has provided a
copy of this Item 77K to PwC. PwC has furnished Registrant with a letter
addressed to the SEC stating that it agrees with the statements made by
Registrant herein. A copy of such letter from PwC is attached hereto as an
exhibit.
For Period Ended 12/31/99
File No. 811-2183
77Q1(f) Letter from independent accountant furnished pursuant to Sub-
Item 77K
[PRICEWATERHOUSECOOPERS LETTERHEAD]
February 23, 2000
Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549
Ladies and Gentlemen:
We have read the statements made by MassMutual Corporate Investors (copy
attached), which we understand will be filed with the Commission pursuant to
Item 77K of the report on From N-SAR for the period ended December 31, 1999.
We agree with the statements concerning our Firm in such Form N-SAR.
Very truly yours,
PricewaterhouseCoopers LLP
Attachment
For Period Ended 12/31/99
File No. 811-2183
Item 77Q2 Information Called for by the Instructions to Sub-Item 77Q2.
During the fiscal year four employees of Massachusetts Mutual Life Insurance
Company (the "Insurance Company"), Registrant's former investment adviser
(now employees of David L. Babson and Company Incorporated, Registrant's
current investment adviser), who had reporting responsibilities with respect
to transactions in securities of Registrant, failed to timely file SEC Form 4
in connection with certain deferrals and transfers to a "shadow account"
under an employee benefit plan of the Insurance Company. Jeanne M. Stamant
failed to timely file one form with respect to three transactions; Mark B.
Ackerman, Treasurer of Registrant, failed to timely file one form with
respect to two transactions; Clifford M. Noreen, Vice President of
Registrant, failed to timely file one form with respect to two transactions;
and Charles C. McCobb, Jr., Vice President and Chief Financial Officer of
Registrant, failed to timely file one form with respect to one transaction.
Stuart H. Reese, President of Registrant, failed to timely file an SEC Form 4
with respect to two transactions that took place in 1998.
