| SC 13G/A | 2010-11-10 | FMR LLC | CORPORATE OFFICE PROPERTIES TRUST | 1,452,343 | 2.4% | EDGAR |
| SC 13G/A | 2010-09-10 | FMR LLC | CORPORATE OFFICE PROPERTIES TRUST | 3,526,867 | 5.9% | EDGAR |
| SC 13G/A | 2010-06-10 | FMR LLC | CORPORATE OFFICE PROPERTIES TRUST | 7,684,641 | 13.0% | EDGAR |
| SC 13G/A | 2010-03-26 | NOMURA ASSET MANAGEMENT CO LTD | CORPORATE OFFICE PROPERTIES TRUST | 1,057,221 | 1.8% | EDGAR |
| SC 13G/A | 2010-03-17 | APG Asset Management US Inc. | CORPORATE OFFICE PROPERTIES TRUST | 2,937,145 | 5.0% | EDGAR |
| SC 13G | 2010-03-11 | APG Asset Management US Inc. | CORPORATE OFFICE PROPERTIES TRUST | 58,386,000 | 5.0% | EDGAR |
| SC 13G/A | 2010-02-16 | FMR LLC | CORPORATE OFFICE PROPERTIES TRUST | 3,967,577 | 6.8% | EDGAR |
| SC 13G | 2010-02-16 | NOMURA ASSET MANAGEMENT CO LTD | CORPORATE OFFICE PROPERTIES TRUST | 3,192,036 | 5.5% | EDGAR |
| SC 13G/A | 2010-02-12 | DAVIS SELECTED ADVISERS | CORPORATE OFFICE PROPERTIES TRUST | 4,242,508 | 7.3% | EDGAR |
| SC 13G | 2010-02-12 | HEITMAN REAL ESTATE SECURITIES LLC | CORPORATE OFFICE PROPERTIES TRUST | 3,885,398 | 6.7% | EDGAR |
| SC 13G/A | 2010-02-04 | VANGUARD GROUP INC | CORPORATE OFFICE PROPERTIES TRUST | 5,335,362 | 9.2% | EDGAR |
| SC 13G | 2010-01-29 | BlackRock Inc. | CORPORATE OFFICE PROPERTIES TRUST | 4,926,689 | 8.5% | EDGAR |
| SC 13G/A | 2010-01-21 | DIAM Co., Ltd. | CORPORATE OFFICE PROPERTIES TRUST | 3,458,400 | 5.9% | EDGAR |
| SC 13G | 2010-01-20 | DIAM Co., Ltd. | CORPORATE OFFICE PROPERTIES TRUST | 3,458,400 | 5.9% | EDGAR |
| SC 13G | 2010-01-19 | DIAM Co., Ltd. | CORPORATE OFFICE PROPERTIES TRUST | 3,458,400 | 5.9% | EDGAR |
| SC 13G | 2009-11-12 | DIAM Co., Ltd. | CORPORATE OFFICE PROPERTIES TRUST | 1,881,489 | 3.6% | EDGAR |
| SC 13G/A | 2009-06-10 | FMR LLC | CORPORATE OFFICE PROPERTIES TRUST | 3,744,469 | 6.5% | EDGAR |
| SC 13G/A | 2009-02-17 | FMR LLC | CORPORATE OFFICE PROPERTIES TRUST | 6,303,519 | 12.2% | EDGAR |
| SC 13G/A | 2009-02-13 | VANGUARD GROUP INC | CORPORATE OFFICE PROPERTIES TRUST | 3,991,686 | 7.7% | EDGAR |
| SC 13G/A | 2009-02-13 | DAVIS SELECTED ADVISERS | CORPORATE OFFICE PROPERTIES TRUST | 2,695,593 | 5.2% | EDGAR |