Riggs National Bank has promoted Barbara Fairfax to vice president and manager of the branch at Walter Reed. Fairfax began as a teller with Riggs 12 years ago and has worked in the training and development section as well as several branches in Washington.

Riggs announced several other promotions. Clifton A. Brown was promoted to vice president and manager of the bank's energy section. Brown joined Riggs in 1972 after obtaining his MBA from George Washington University.

Promoted to assistant vice presidents were Tony E. Hayden in operations and Carol A. Wagner in real estate, New assistant vice presidents from the metropolitan division are Mildred L. Elrod, Carol J. Lichenstein, Elizabeth L. Reber and Dennis E. Berry.

William E. Simon, former secretary of the Treasury, was elected to the board of governors of the Commodity Exchange. Simon is the second public representative to be named to the 25-member Comex board.

Kevin McEnery has been named vice president of Newsweek International. The appointment of Jane Strauss to the new post of advertising manager, administration, also was announced.

The Federal Home Loan Mortgage Corp. announced the appointment of William H. Boyle to vice president of corporate planning and development. Other promotions include Richard M. Webb, appointed to director of adminstration, and Hilary Reilly to manager of corporate information systems.

Edwin D. Brooks, Jr. is one of two businessmen nominated for the top offices in the United States League of Savings Associations. Brooks, of Richmond, was nominated for league president and served last year as the group's vice president.

Stanley Ebner has been named vice president and manager of Northrop Corp. in Arlington.

Gerald A. Zulli has been transferred to the Washington office of Deloitte Haskins & Sells. He was previously based in Wilmington, Del.

Mark M. Cameron has been promoted to account executive with the local public relations firm of Harshe-Rotman & Druck.

T. Rowe Price Associates Inc. of Baltimore announced several corporate changes and promotions. Robert E. Hall was elected president, succeeding Cornelius C. Bond Jr., who will devote full time to his appointment as chairman of the advisory firm's finance committee. George A. Roche assumes Hall's former position as president of the Rowe Price new era fund. Both Hall and Roche were elected directors of the growth stock fund and the new era fund.

Larry H. Bacon has been named director of public affairs for the Farm Credit Administration. Bacon joined FCA in 1974 and has served in various capacities in the agency's office of supervision.

Constance Cornell Stuart, former White House press secretary to Pat Nixon, has joined Racal Airstream Inc. of Rockville as manager of public relations and government affairs.

Charles M. Matheson was promoted to vice president, controller, and Donna K. Ours moved up to assistant accounting officer of the National Bank of Fairfax.