Jerry E. Epstein has been named to the new position of director of business development for The Washington Post Co. Epstein will be responsible for helping to identify and evaluate new business opportunities for the company. He was previously in the San Francisco office of The Boston Consulting Group Inc., a management consulting firm.

Alvaro Rizo-Castellon has been named a director of the international division of Fraser/Associates. He has been minister, counselor and first secretary of the Nicaraguan embassy here.

Brian Conboy, Washington counsel for Time Inc., has been elected vice president of government affairs for the company.

Jennifer Prill has been promoted to chief operating officer of the Airline Publishing Group Inc., publisher of Airline Executive and Commuter Air magazines. She was formerly vice president and general services manager of the firm. In addition, Joseph S. Murphy has been promoted to executive publisher. He has been editor and publisher of Airline Executive.

Stephen M. Day has been appointed vice president of marketing and planning for Comsat General Corp. He was formerly European sales manager of electronic products for the photo products department of E. I. du Pont de Nemours & Co.

In a related development, Alfred P. Statham was elected vice president of corporate affairs at Comsat. He has been vice president of public affairs for Inco Ltd. in Toronto.