Two major department-store chains -- Nordstrom Inc. and Bambergers, a division of Macy's -- will open new stores at Pentagon City in south Arlington as part of their entry into the Washington retail market.

The two stores will be the anchors for a new mall at Pentagon City aimed at upscale shoppers in Northern Virginia and the District, the project's developers announced yesterday.

The mall, which is expected to open its doors in 1989, is a joint development of Rose Associates, a New York real estate development firm, and Melvin Simon & Associates, an Indianapolis company that has built more than 120 shopping centers.

The Pentagon City complex will also include about 150 other retail stores, a nine-story office building, and a luxury hotel organized around a four-level, sky-lit open area that is designed to have the feel of a 19th-century conservatory.

Construction of the mall, which will be known as The Fashion Centre, will cost in excess of $100 million, the developers estimated.

Plans have been in the works since 1976 for the phased development of the 116-acre tract of land surrounding the Pentagon City Metro station just west of Crystal City, the largest piece of undeveloped land in Arlington. Two office buildings, occupied by MCI Telecommunications Corp., already have been constructed.

The completion of new buildings announced yesterday is expected to generate millions in new tax revenue for the city of Arlington, as well as trigger more fierce competition among department stores and shopping malls around the area for the dollars of affluent shoppers.

The Pentagon City stores would be the second in the region for both Bambergers and Nordstrom, a Seattle-based retailer that has chosen the Washington area for its first East Coast expansion. Nordstrom previously announced that it would locate a store in the expanded Tysons Corner Shopping Center in Fairfax County. Bambergers has said it will locate a store in the planned Tysons II shopping mall nearby.

Officials for both chains yesterday said they are looking at other possible sites in the area.

"Our type of customer is definitely here," said Nordstrom cochairman John R. Nordstrom, citing the large number of affluent professionals living in the region.

"We think that Pentagon City is one of the most exciting projects we've ever been involved with."

"They Nordstrom and Bambergers definitely bring very strong competition to the area. But we're not automatically going to change our current strategy except to try to do what we do better," said J. Warren Harris, chairman of the Hecht Co., one of the area's largest department-store chains.

One Washington retail expert said the mall itself also should provide fierce competition for other retail centers near the city, although it should not pose as much of a threat to the large suburban malls such as Tysons Corner.

"I can't imagine people driving further into town," said this source, who asked to be unidentified. But, he added, "Pentagon City has an opportunity to be getting awfully close to a downtown type of setting. What they would hope to do . . . is to draw people out of the District of Columbia on the subway system."

Officials in Arlington, where civic groups had once fought the Pentagon City project on the grounds that it would add to traffic congestion and pollution, also hailed the development, saying it would produce hundreds of news jobs and at least $5 million in yearly tax revenues.

"It's something we've been needing for a long time," said Mary Margaret Whipple, chairman of the Arlington County Board.

New mall construction at Pentagon City is scheduled to begin this fall. Officials said the project will include a 4,524-car parking garage, and more than 5,000 residential units surrounding the mall as well as the hotel.