<PAGE>
THIS FILING LISTS SECURITIES HOLDINGS REPORTED
ON THE FORM 13F FILED ON FEBRUARY 14, 2000
PURSUANT TO A REQUEST FOR
CONFIDENTIAL TREATMENT AND FOR WHICH
THAT REQUEST
EXPIRED ON AUGUST 14, 2000
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form 13F
FORM 13F COVER PAGE
Report for the Calendar Year or Quarter Ended: December 31, 1999
Check here if Amendment [x ]; Amendment Number: 2
This Amendment (Check only one.): [ ] is a restatement.
[x] adds new holdings entries.
Institutional Investment Manager Filing this Report:
Name: Chesapeake Partners Management Co., Inc.
Address: 1829 Reisterstown Road
Suite 220
Baltimore, Maryland 21208
Form 13F File Number: 28-4120
The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.
Person Signing this Report on Behalf of Reporting Manager:
Name: Mark D. Lerner
Title: Vice President
Phone: (410) 602-0195
Signature, Place, and Date of Signing:
/s/ Mark D. Lerner Baltimore, Maryland 8/14/00
------------------ ------------------- -------
[Signature] [City, State] [Date]
Report Type (Check only one.):
[X] 13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager
are reported in this report.)
[ ] 13F NOTICE. (Check here if no holdings reported are in this report, and all
holdings are reported by other reporting manager(s).)
[ ] 13F COMBINATION REPORT. (Check here if a portion of the holdings for this
reporting manager are reported in this report and a portion are reported
by other reporting manager(s).)
<PAGE>
FORM 13F SUMMARY PAGE
Report Summary:
Number of Other Included Managers: 0
-----------------------------
Form 13F Information Table Entry Total: 16
------------------------------
Form 13F Information Table Value Total: $378,386
-----------------------------
(thousands)
List of Other Included Managers:
Provide a numbered list of name(s) and Form 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.
[If there are no entries in this list, state "NONE" and omit the column headings
and list entries.]
None
<PAGE>
FORM 13F INFORMATION TABLE
<TABLE>
<CAPTION>
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7
--------------------- -------- ---------- -------- --------------------------- ---------- --------
TITLE OF VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER
NAME OF ISSUER CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGERS
<S> <C> <C> <C> <C> <C> <C> <C> <C>
Atlantic Richfield Common 048825103 76,250 881,500 SH SOLE
------------------------------------------------------------------------------------------------------------------------
Comsat Corp. Common 20564D107 9,584 482,220 SH SOLE
------------------------------------------------------------------------------------------------------------------------
Foamex International Common 344123104 1,885 226,800 SH SOLE
------------------------------------------------------------------------------------------------------------------------
GTE Corp Common 362320103 11,290 160,000 SH SOLE
------------------------------------------------------------------------------------------------------------------------
Hannaford Brothers Common 410550107 53,579 773,000 SH SOLE
------------------------------------------------------------------------------------------------------------------------
Howmet International Common 443208103 2,016 111,600 SH SOLE
------------------------------------------------------------------------------------------------------------------------
MCN Energy Group Common 55267J100 1,275 53,700 SH SOLE
------------------------------------------------------------------------------------------------------------------------
MediaOne Common 58440J104 91,845 1,195,700 SH SOLE
------------------------------------------------------------------------------------------------------------------------
Monsanto Common 611662107 1,772 50,000 SH CALL SOLE
------------------------------------------------------------------------------------------------------------------------
Shorewood Packaging Common 825229107 2,473 130,600 SH SOLE
------------------------------------------------------------------------------------------------------------------------
United Water Common 913190104 3,125 91,400 SH SOLE
------------------------------------------------------------------------------------------------------------------------
US West, Inc. Common 91273H101 74,959 1,041,100 SH SOLE
------------------------------------------------------------------------------------------------------------------------
US West, Inc. Common 91273H101 7,200 100,000 SH CALL SOLE
------------------------------------------------------------------------------------------------------------------------
Warner Lambert Common 934488107 33,594 410,000 SH SOLE
------------------------------------------------------------------------------------------------------------------------
Warner Lambert Common 934488107 2,458 30,000 SH CALL SOLE
------------------------------------------------------------------------------------------------------------------------
AT&T Common 001957109 5,081 100,000 SH PUT SOLE
------------------------------------------------------------------------------------------------------------------------
<CAPTION>
COLUMN 1 COLUMN 8
--------------------- -------------------------------
VOTING AUTHORITY
NAME OF ISSUER SOLE SHARED NONE
<S> <C> <C> <C>
Atlantic Richfield SOLE
------------------------------------------------------------------
Comsat Corp. SOLE
------------------------------------------------------------------
Foamex International SOLE
------------------------------------------------------------------
GTE Corp SOLE
------------------------------------------------------------------
Hannaford Brothers SOLE
------------------------------------------------------------------
Howmet International SOLE
------------------------------------------------------------------
MCN Energy Group SOLE
------------------------------------------------------------------
MediaOne SOLE
------------------------------------------------------------------
Monsanto NONE
------------------------------------------------------------------
Shorewood Packaging SOLE
------------------------------------------------------------------
United Water SOLE
------------------------------------------------------------------
US West, Inc. SOLE
------------------------------------------------------------------
US West, Inc. NONE
------------------------------------------------------------------
Warner Lambert SOLE
------------------------------------------------------------------
Warner Lambert NONE
------------------------------------------------------------------
AT&T NONE
------------------------------------------------------------------
</TABLE>
