Directors of Commerce Bank & Trust in Bethesda have elected James J. Cromwell chairman of the bank.

The Montgomery County attorney has been a member of the Commerce board since the bank was founded in 1974.

Commerce B&T, a Mercantile Bankshare Corp. affiliate with assess of approximately $11.6 million, reached an agreement for a proposed merger with Potomac National Bank in December. The banks' combined assets total $50 million.

Continued evidence of the transition of power to the new administration comes in two announcements.

Federal Railroad Administrator Asaph H. Hall resigned his position effective Jan. 20 and announced be would begin work today at General Dynamics' St. Louis headquarters.

Hall joined the Transportation Department in 1969 after spending 12 years with Westinghouse Electric Corp. He has been Federal Railroad Administrator since 1974.

Data Resources, Inc. announced the appointment of Joseph E. Kasputys as vice president with responsibility for the company's Washington area clients.

Kasputys is the former Assistant Secretary for Administration in the Commerce Department, where he has been a top official for five years.

Communications Satellite Corp. director Frederic G. Donner announced his retirement from that post after 12 years of service.

Donner noted in his letter of resignation to President Ford that his 12 years on the board "spanned virtually the entire life of Comsat."

The Comsat board has designated Donner "director emeritus," the first so designated.

The Hecht Co. has named Douglas Coffey senior vice president and director of personnel.

Coffey joins the Washington department store after ten years with other May Co. department stores in Cleveland and Youngstown, Ohio.

Flow Laboratories, Inc. in McLean has promoted William A. Knapp Jr. to vice president, Dr. Knapp came to Flow Laboratories in 1971 from Hazelton Laboratories, Inc.

General Research Corp. has elected Harrison N. Hoppes vice president. Hoppes originally joined Research Analysis Corp. in 1960 and remained with the company when it was acquired by General Research in 1972.

American Finance System, Inc. in Silver Spring has named John J. Krieger executive vice president and chief finance in 1962 and has been senior vice-president and chief financial officer since March 1976.

In a related move. American Finance selected Bruce T. Cunningham to head American Finance Management Corp. and named Gordon J. Thomasch senior vice president.

Cunningham and Thomasch both originally joined Equitable Credit Corp. and joined AFS in 1959 when the two companies merged.

Promotions at First National Bank of Maryland include W. Howard Hayman and E. Mason Hendrickson, who become senior vice presidents, and Edgar Dianderas and David C. Sharman, who are new vice presidents.

Hayman heads the bank's Wiscomico County region, which includes six offices. Hendrickson is in charge of the six offices in the bank's Washington County region.

John R. Burwell is a new vice president at American Security Bank. Burwell came to American Security last month and heads the bank's new division of General Services.

Directors: Home Federal Savings & Loan Association of Washington has elected Vincent E. Reed, superintendent of Washington D.C. public schools, to the board of directors.

Dr. William A. McNamara joins the board of Bank of Bethesda.

Three new directors at Guaranty Bank & Trust in Fairfax are John F. Carman, John B. Contristan and James N. Newsome.

Bank of Virginia Co. named Elizabeth G. Helm a director. She is chairman of Bank of Virginia-Shenandoah and a director of Bank of Virginia-Potomac. Both are affiliates of the Richmond-based company.