SEC FORM 4/A

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

HAMLIN CLAY W III

(Last)

(First)

(Middle)

424 MULBERRY LANE

(Street)

HAVERFORD

19041

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
CORPORATE OFFICE PROPERTIES TRUST [ OFC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	CEO and Trustee

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2004

4. If Amendment, Date of Original Filed (Month/Day/Year)
08/13/2004

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Units of Corporate Office Properties, L.P.	08/11/2004		C		120,000	D	⁽¹⁾	3,729,330⁽²⁾	D⁽³⁾
Common Stock of Corporate Office Properties Turst	08/11/2004		A		120,000	A	⁽¹⁾	130,000	I	10000 held in IRA Account and 120000 owned by LBCW Limited Partnership
Common Stock of Corporate Office Properties Trust	08/11/2004		D		25,200	D	$24.752	104,800⁽⁴⁾	I⁽⁴⁾	Shares sold were owned by LBCW Limited Partnership

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. Common Units of Corporate Office Properties, L.P. convert on a one-for-one basis into common shares of Corproate Office Properties Trust

2. Units that were converted were owned by LBCW Limited Partnership

3. After conversion, 3,729,330 Units are owned as follows: 3,041,427 owned by LBCW Limited Partnership, 566,492 owned by Clay W. Hamlin and 121,411 owned by Lynn Hamlin**

4. After Sale, Shares are owned as follows: 10,000 held in IRA Account and 94,800 held by LBCW Limited Partnership.

	Karen M. Singer, by Power of Attorney	08/12/2004
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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