Geioc Corp. President and Chairman of the Board John J. Byrne has been elected to the board of directors of Potomac Electric Power Co.

Byrne also is the chairman of the board of an affiliated company, Government Employees Insurance Co., and a director of two other affiliates, Government Employees Life Insurance Co. and Criterion Insurance. He is also a board member of the Martin Mareitte Corp.

Before joining GEICO, Byrne was executive vice president of the Travelers Insurance Co. in Hartford, Conn. He is a member of the Society of Actuaries and a Chartered Life Underwriter.

Michelle C. White has been appointed special assistant for civil rights in the Office of Customer and Community Programs of the Comptroller of the Currency.

Edith Smith has been named fitness director of the Bethesda Racquet & Health Club.

J. Owen Cole, chairman of the board of the First Maryland Bancorp and the First National Bank of Maryland, Baltimore, has been elected to the board of directors of Black & Decker Inc.

Ethel Morehead has been promoted to sales manager of the Washington district Prudential Insurance Co.

Betty Garvey has been named manager of the Oxon Hill office of Hugh T. Peck Properties Inc. Realtors. She has been a million-dollar sales associate at Peck since joining the company in 1974.

Kristin M. Smith has been appointed director of business development of Interspace Inc./Washington, a unit of a national interior design and space planning firm.

Robert Hermann has joined the Washington public relations office of The American Legion. He resigned from the Department of Energy to accept the new position and previously spent 29 years in the U. S. Air Force, retiring as a colonel.

Carleton M. Stewart, chairman of the board of American Security Bank, has been named to the Presidential Commission on U. S.-Liberian relations.