Eastern Airlines announced yesterday it will return to Dulles International Airport Nov. 1, after a two-year absence, and operate four roundtrip flights daily.

The new flights--two to the airline's hub at Atlanta and one each to Ottawa and Wilkes-Barre, Pa.--come as other carriers are adding service at the under-used airport. Dulles is being promoted by both the federal government and private groups.

Eastern spokesman Paula Musto said that business and residential growth near Dulles and a new expressway that will cut travel time from downtown Washington have convinced the airline that it will find a strong market at the airport.

Eastern now operates 65 daily departures, plus extra sections, from National Airport and 16 each day from Baltimore-Washington International Airport. "We need to balance our system out with Dulles," she said. "It's sort of a missing link."

Eastern had as many as 19 departures a day from Dulles in the 1960s, but gradually cut back service because it could not attract enough passengers, Musto said. Eastern canceled its last Dulles flight in the fall of 1981 as part of nationwide revisions in flight patterns forced by the air traffic controllers' strike.

Recently, use of Dulles has grown steadily. About 2.7 million passengers used the airport in the year ending March 31, 16 percent more than than in the year ended March 31, 1982. Landings and take-offs increased by about 11 percent.

American Airlines and United Airlines have added six flights to Chicago. People Express and Western Airlines began their operations at Dulles. USAir has announced plans to begin serving the airport in November, with flights to its Pittsburgh hub.

Carriers continue to view National, which serves about 13.5 million people a year, as the primary market in the Washington area. They say Dulles is inconvenient for many business travelers and poorly designed to handle a large number of short-haul flights.

The Federal Aviation Administration, which owns Dulles, is considering major construction at the airport to try to remove concerns about its lay-out. Planners have suggested building a separate terminal to handle short-haul flights.

The FAA is now completing an expressway between Interstate 66 and the Dulles Access Road. It has also put in traffic quotas at National to force passenger growth to Dulles and BWI.