The following firms have filed for bankruptcy protection recently with local clerk of court offices of the U.S. Bankruptcy Court.

Under Chapter 11 of the federal bankruptcy code, a company is protected from claims by creditors while it attempts to reorganize its finances under a plan approved by the court. In a Chapter 7 liquidation, a court trustee sells assets to pay creditors' claims. The company then ceases operations.

Rockville Court Maryland District

North Oak Professional Park Inc. of 3000 Mitchellville Rd., Bowie, was the subject of an involuntary Chapter 11 petition Aug. 21. Three parties, North Oak Professional Park Townhouse Condominium Association, North Oak Professional Park Medical Condominium Association and Sheffield Construction Co., alleged the firm collectively owed them about $48,000.

Designs in Wood Inc., doing business as Mills Lumber & Supply Co., Rose Hill Hardware and Frederick Hardware of 9700 Livingston Rd., Fort Washington, filed for Chapter 11 reorganization Aug. 21. The company listed $253,431.84 in claims held by its largest unsecured creditors.

Fort Knox Plaza L.P. and Fort Knox Land L.P., both of 6931 Arlington Rd., Suite 401, Bethesda, filed for Chapter 11 reorganizations Aug. 20. The real estate investment and development firms each listed assets and liabilities as being more than $1 million. Fort Knox Land said it owed North Carolina Savings and Loan Association F.A. $1.4 million and Fort Knox Plaza said it owed the savings and loan $6.9 million.

Alexandria Division Eastern District of Virginia

Interstate Truck Body & Repair Inc., doing business as Interstate Truck Center at 9108 Owens Dr., Manassas, filed for Chapter 11 reorganization Aug. 20. The truck repair company listed assets of $1.4 million and liabilities of $1.3 million.

Chain Bridge Association of 4160 Chain Bridge Rd., Fairfax, was the subject of an involuntary Chapter 7 petition filed Aug. 20 by a partner of the association. The firm, which owns real estate at 4160 Chain Bridge Rd., faced a foreclosure sale the day it filed for bankruptcy protection.

Olson Foreign Auto Service of P.O. Box 10701, McLean, filed for Chapter 7 liquidation Aug. 20. The firm listed $78,978.58 in claims held by unsecured creditors.

District of Columbia

Felton, Hargess, Severson Associates Inc. of 1629 K St., Suite 800, filed for Chapter 7 liquidation Aug. 21. The advertising agency listed assets of $7,000 and liabilities of $250,000.