SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

 

(Rule 13d-102)

 

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED

(AMENDMENT 1)

 

CORPORATE OFFICE PROPERTIES TRUST

(NAME OF ISSUER)

 

COMMON STOCK

(Title of Class of Securities)

 22002T108

(CUSIP Number)

 

(Date of Event Which Requires Filing of this Statement)

 

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

 

 

X Rule 13d-1 (b)

 

 

Rule 13d-1 (c)

 

 

Rule 13d-1 (d)

 

CUSIP No. 22002T108

13G/A

Page 1 of 3 pages

1.

Names of reporting persons

Security Capital Research & Management Inc.

 

I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

36-4130398

 

2.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

(a)

 

 

(b)

3.

SEC USE ONLY

4.

CITIZENSHIP OR PLACE OF ORGANIZATION

 

Delaware

 

NUMBER OF

5.

SOLE VOTING POWER

1,336,181

SHARES

 

 

 

BENEFICIALLY

6.

SHARED VOTING POWER

143,600

OWNED BY

 

 

 

EACH

7.

SOLE DISPOSITIVE POWER

1,834,681

REPORTING

 

 

 

PERSON WITH

8.

SHARED DISPOSITIVE POWER

143,600

 

9.

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 

1,978,281

10.

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES

 

 

CERTAIN SHARES

 

 

11.

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

 

5.4%

 

12.

TYPE OF REPORTING PERSON*

IA

 

Item 1(a).

Name of Issuer:

 

CORPORATE OFFICE PROPERTIES TRUST

Item 1(b).

Address of Issuer's Principal Executive Offices:

 

8815 CENTRE PARK DRIVE, SUITE 400

 

 COLUMBIA, MARYLAND 21045

Item 2(a).

Name of Person Filing:

 

Security Capital Research & Management Inc.

Item 2(b).

Address of Principal Business Office or, if None, Residence:

 

10 SOUTH DEARBORN STREET, SUITE 1400

 

CHICAGO, ILLINOIS 60603

Item 2(c).

Citizenship

 

Delaware

Item 2(d).

Title of Class of Securities:

 

COMMON STOCK

 

Unless otherwise noted, security being reported is common stock

Item 2(e).

CUSIP Number:

 

Item 3

If this Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b)

 

Or (c), Check Whether the Person Filing is a :

 

(a)

 

Broker or dealer registered under Section 15 of the Exchange Act;

 

(b)

 

Bank as defined in Section 3(a)(6) of the Exchange Act;

 

(c)

 

Insurance company as defined in Section 3(a)(19) of the

 

 

 

Exchange Act;

 

(d)

 

Investment company registered under Section 8 of the Investment

 

 

 

Company Act;

 

(e)

X

An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

 

(f)

 

An employee benefit plan or endowment fund in accordance with

 

 

 

Rule 13d-1(b)(1)(ii)(F);

 

(g)

 

A parent holding company or control person in accordance with

 

 

 

Rule 13d-1(b)(1)(ii)(G);

 

(h)

 

A savings association as defined in Section 3(b) of the Federal

 

 

 

Deposit Insurance Act;

 

(i)

 

A church plan that is excluded from the definition of an

 

 

 

Investment company under Section 3(c)(14) of the Investment

 

 

 

Company act;

 

(j)

 

Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If this statement is filed pursuant to Rule 13d-1(b), check this box.

X

 

Page 2 of 3 pages

Item 4.

Ownership

 

Provide the following information regarding the aggregate number and

 

Percentage of the class of securities of issuer identified in Item 1.

 

(a)

Amount beneficially owned: 1,978,281

 

 

Including 0 shares where there is a Right to Acquire.

 

(b)

Percent of class: 5.4%

 

(c)

Number of shares as to which such person has:

 

 

(i)

Sole power to vote or to direct the vote:

1,336,181 

 

 

(ii)

Shared power to vote or to direct the vote:

143,600 

 

 

(iii)

Sole power to dispose or to direct the disposition of:

1,834,681 

 

 

(iv)

Shared power to dispose or to direct the disposition of:

143,600 

 

Item 5.

Ownership of Five Percent or Less of a Class. NOT APPLICABLE

If this statement is being filed to report the fact that as of the date

hereof the reporting person has ceased to be the beneficial owner of more

 

 

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

 

Security Capital Research & Management Inc. is the beneficial owner of 1,978,281 shares of the

issuer's common stock on behalf of other persons known to have one or more of

the following:

 

the right to receive dividends for such securities;

 

the power to direct the receipt of dividends from such securities;

 

the right to receive the proceeds from the sale of such securities;

 

the right to direct the receipt of proceeds from the sale of such securities;

No such person is known to have an interest in more than 5% of the class of

securities reported herein unless such person is identified below.

 

Item 7.

Identification and Classification of the Subsidiary Which Acquired the

 

Security being reported on by the Parent Holding Company.

Not Applicable

 

 

 

 

 

Item 8.

Identification and Classification of Members of the Group.

 

Not Applicable

 

Item 9.

Notice of Dissolution of Group.

 

Not Applicable

 

Item 10.

Certifications

 

By signing below I certify that, to the best of my knowledge and belief,

the securities referred to above were not acquired and are not held for the

purpose of or with the effect of changing or influencing the control of the

issuer of the securities and were not acquired and are not held in connection

with or as a participant in any transaction having that purpose or effect.

 

 

Page 3 of 3 pages 

 

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the

information set forth in this statement is true, complete and correct.

Dated: FEBRUARY 15,2005

Security Capital Research & Management Inc.

 

By: /s/ Genine M. Dawczak

 

--------------------------------------

 

Genine M. Dawczak

 

Assistant Controller

 

 

 

 

The original statement shall be signed by each person on whose behalf the statement

is filed or his authorized representative. If the statement is signed on behalf of

a person by his authorized representative (other than an executive officer or general

partner of the filing person), evidence of the representative's authority to sign on

behalf of such person shall be filed with the statement, provided, however, that a

power of attorney for this purpose which is already on file with the commission may

be incorporated by reference. The name and any title of each person who signs the

the statement shall be typed or printed beneath his signature.