Insider Transactions is a weekly report of stock transactions involving officers and directors of publicly owned local companies.

Stock trading by corporate insiders often is a bellwether of corporate health. Most insiders buy stock or exercise options to make a profit. And insiders may be selling stock for tax reasons, estate planning or cash needs.

The following insider transactions involving local companies were compiled by States News Service from reports to the Securities and Exchange Commission.

ATLANTIC RESEARCH CORP. Keith B. Mullin, a vice president of Atlantic Research of Alexandria, disposed of his entire 3,524 common-share stake in the company. Mullin sold the stock in a private transaction on Dec. 22.

BDM INTERNATIONAL INC. Charles R. Wasaff, a vice president of McLean-based BDM International, exercised an option to acquire 3,600 shares of the company's class A common stock on Dec. 21. Wasaff now holds 161,500 class A common shares directly.

BIOTECH RESEARCH LABORATORIES INC. Robert C. Ting, an officer and a director of Biotech Research Laboratories of Rockville, disposed of 5,000 company common shares in an open-market sale on Dec. 15. Ting now holds 617,000 common shares directly and 94,000 common shares indirectly.

DANAHER CORP. M. Teri Lynch, an officer of Washington-based Danaher, purchased 2,000 company common shares in an open-market transaction on Jan. 11. Lynch now holds 10,200 common shares directly.

GANNETT CO. INC. Maurice L. Hickey, an affiliate of Gannett, exercised options to acquire 7,125 common shares of the Arlington-based company on Dec. 31. Hickey currently holds 23,743 common shares directly.

GENERAL PHYSICS CORP. Robert W. Deutsch, chairman of Columbia-based General acquired 2,000 company common shares in an open-market purchase on Dec. 28. Deutsch currently owns 2,000 common shares directly.

MANOR CARE INC. Allen W. Mathis Jr., a director of Manor Care of Silver Spring, purchased 1,000 company common shares in an open-market transaction on Oct. 20. Mathis now owns 14,500 common shares directly and 10,000 common shares indirectly.

Robert L. Wilkie, an affiliate of the company, purchased 1,000 company common shares in an open-market transaction on Jan. 13. Wilkie currently holds 19,613 common shares directly and 2,337 common shares indirectly.

MARRIOTT CORP. Paul Novak, a vice president of Bethesda-based Marriott, sold 1,000 company common shares in an open-market transaction on Dec. 31. Novak now holds 11,102 common shares directly.

MICROS SYSTEMS INC. Leonard Weintraub, a director of Micros Systems of Beltsville, sold 2,000 company common shares in an open-market transaction on Dec. 23. Weintraub now holds 236,000 common shares directly.

MITEL CORP. Terence H. Matthews, a shareholder of Silver Spring-based Mitel, sold 515,100 company common shares on the open market between Nov. 2 and Nov. 27. Matthews currently owns 1.34 million common shares directly and 721,600 common shares indirectly.

ROUSE CO. Richard B. Armiger, a vice president of Rouse of Columbia, sold 15,000 company common shares in an open-market transaction on Jan. 6. Armiger now owns 13,500 common shares directly.

RYLAND GROUP INC. James W. Rouse, a director of Ryland Group of Columbia, sold his entire 4,000 common-share stake in the company. Rouse sold the stock in an open-market transaction on Dec. 29.