The Top 25 Office Owners survey includes office space owned globally as of Dec. 31, 2010. If companies had interests in mixed-use projects, they were asked to provide the totals for the office portion only.

  1. RREEF

    Total Office Portfolio: 71.9 million sq. ft.

    Phone: (212) 454-6260

    Website: www.rreef.com

  2. Brookfield Office Properties

    Total Office Portfolio: 69.3 million sq. ft.

    Phone: (212) 417-7000

    Website: www.brookfieldofficeproperties.com

  3. The Blackstone Group

    Total Office Portfolio: 65.6 million sq. ft.

    Phone: (212) 583-5000

    Website: www.blackstone.com

  4. CB Richard Ellis Investors

    Total Office Portfolio: 62.7 million sq. ft.

    Phone: (213) 683-4200

    Website: www.cbreinvestors.com

  5. Hines

    Total Office Portfolio: 59.2 million sq. ft.

    Phone: (713) 621-8000

    Website: www.hines.com

  6. LaSalle Investment Management

    Total Office Portfolio: 42.8 million sq. ft.

    Phone: (312) 782-5800

    Website: www.lasalle.com

  7. TIAA-CREF

    Total Office Portfolio: 42.1 million sq. ft.

    Phone: (800) 842-2733

    Website: ww.tiaa-cref.org

  8. Boston Properties

    Total Office Portfolio: 38.4 million sq. ft.

    Phone: (617) 236-3300

    Website: www.bostonproperties.com

  9. Vornado Realty Trust

    Total Office Portfolio: 35.2 million sq. ft.

    Phone: (212) 894-7000

    Website: www.vno.com

  10. Duke Realty Corp.

    Total Office Portfolio: 34.7 million sq. ft.

    Phone: (317) 808-6000

    Website: www.dukerealty.com

  11. Mack-Cali Realty Corp.

    Total Office Portfolio: 31.8 million sq. ft.

    Phone: (732) 590-1000

    Website: www.mack-cali.com

  12. Brandywine Realty Trust

    Total Office Portfolio: 30.5 million sq. ft.

    Phone: (610) 325-5600

    Website: www.brandywinerealty.com

  13. CommonWealth REIT

    Total Office Portfolio: 29.5 million sq. ft.

    Phone: (617) 332-3990

    Website: www.cwhreit.com

  14. SL Green Realty Corp.

    Total Office Portfolio: 29.1 million sq. ft.

    Phone: (212) 594-2700

    Website: www.slgreen.com

  15. Behringer Harvard

    Total Office Portfolio: 28.1 million sq. ft.

    Phone: (214) 655-1600

    Website: www.behringerharvard.com

  16. Liberty Property Trust

    Total Office Portfolio: 26.6 million sq. ft.

    Phone: (610) 648-1700

    Website: www.libertyproperty.com

  17. Highwoods Properties

    Total Office Portfolio: 25 million sq. ft.

    Phone: (919) 872-4924

    Website: www.highwoods.com

  18. Shorenstein Properties

    Total Office Portfolio: 22.3 million sq. ft.

    Phone: (415) 772-7000

    Website: www.shorenstein.com

  19. Wells REIT II

    Total Office Portfolio: 22.1 million sq. ft.

    Phone: (770) 449-7800

    Website: www.wellsreitii.com

  20. Corporate Office Properties Trust

    Total Office Portfolio: 21.3 million sq. ft.

    Phone: (443) 285-5400

    Website: www.copt.com

  21. Piedmont Office Realty Trust

    Total Office Portfolio: 21.2 million sq. ft.

    Phone: (770) 418-8800

    Website: www.piedmontreit.com

  22. ING Clarion Partners

    Total Office Portfolio: 20.6 million sq. ft.

    Phone: (212) 883-2500

    Website: www.clarionpartners.com

  23. KBS Realty Advisors

    Total Office Portfolio: 19.4 million sq. ft.

    Phone: (949) 417-6500

    Website: www.kbsrealty.com

  24. The Inland Real Estate Group of Cos.

    Total Office Portfolio: 18 million sq. ft.

    Phone: (630) 218-8000

    Website: www.inlandgroup.com

  25. AEW Capital Management

    Total Office Portfolio: 16.4 million sq. ft.

    Phone: (617) 261-9000

    Website: www.aew.com