Allegheny Beverage Corp., the Cheverly-based contract food service company, has tapped John E. Baker as senior vice president and chief financial officer. Baker, an accountant and graduate of Columbia University Business School, was senior vice president of John Blair Marketing Inc. in New York and held senior posts with City Investing Co., an international holding company. In May, Allegheny, in a major corporate restructuring, bought Servomation Corp., a Stamford, Conn.-based food service company, from City Investing for $225 million. The acquisition of Servomation, which will be merged with Allegheny's Macke food service operations to form the Service America Corp., makes Allegheny the largest publicly owned food-service company in the country. Other company operations include building maintenance, laundry services and office furniture retailing.

The Hyatt Regency Bethesda, the 384-room luxury hotel that will open in the Bethesda Metro Center on Nov. 1, has named as its general manager James E. Beard, formerly general manager of the Hyatt Richmond. Other appointments include: F. Wayne Knowles, executive chef; Surinder K. Duggal, controller; Jeri Roche, director of catering; Lani Murayama, director of personnel; Wayne Mollohan, director of engineering; Jonathan Eber, director of sales; Jeannette E. Hinz, sales manager; Brett N. Topham, sales manager; Richard P. Carbone, executive assistant manager for food and beverage, and Daniel J. Amato, executive assistant manager for rooms.

The Sheraton Washington Hotel on Woodley Road off Connecticut Avenue has reorganized its sales staff along geographical lines, naming former national sales account manager Mary Power director of the department. Power, who will handle local sales accounts, succeeds Jack Earnshaw, who has been appointed director of sales for the Sheraton Corp.'s new hotel in Walt Disney World Village in Orlando, Fla., a $175 million property scheduled to open in 1988. William C. Gehron, formerly corporate sales account manager for the Sheraton, has become sales director at the Omni Shoreham Hotel.