The last buses will pull out of the District's Greyhound Bus Terminal on Aug. 4, leaving empty the 47-year-old Art Deco landmark that has been termed the "Ellis Island of Washington," Greyhound Lines Inc. officials announced yesterday.

Greyhound, which has received temporary government approval for its proposed $80 million acquisition of Trailways Lines Inc., plans to move its bus service to the Trailways terminal at First and L streets NE, near Washington Union Station, a spokesman said.

Greyhound plans to operate buses under the Trailways and Greyhound names, with no cuts in service, said David W. Batchelor, president of the company's eastern division.

The company has not determined how many terminal jobs will be cut because of the local consolidation, Batchelor said. The two terminals employ about 55 people. About a dozen maintenance jobs will be cut when Greyhound combines the two local maintenance operations, which employ 97, he said.

The Greyhound terminal, a registered historic landmark, may serve as the foundation for a 12-story office building on the site, 12th Street and New York Avenue NW, according to the plans of Carlyle Associates, the New York real estate developer that owns the building.

Greyhound sold the property, situated in the booming real estate market surrounding the Washington Convention Center, to Carlyle and a local developer, Michael Hadid, in 1985 for $21 million. Greyhound, owned by GLI Acquisition Co. of Dallas, has leased the terminal since then, but said last year that it planned to move.

Carlyle, which later purchased Hadid's share, is considering plans for an office and retail complex that would incorporate elements of the building's original Art Deco facade, which was covered in 1976 by aluminum and cement, said Christopher Collins, an attorney for the developer.

The station, called the "Grand Central" of the motor bus world when it opened in 1940, was one of several Greyhound bus stations designed in the 1930s and '40s by architect William S. Arrasmith.

The Art Deco Society of Washington and the D.C. Preservation League fought for the building to be declared a landmark, despite its current exterior.

Because of the landmark status, any building plans would have to be reviewed by the D.C. Preservation Review Board.