Brooks Brothers is planning to take over two store locations from Lewis & Thomas Saltz and, for the first time, will expand into the Washington suburbs.

The Saltz stores at 5500 Wisconsin Ave. in Chevy Chase and in the Tysons Corner shopping center will close at the end of this month, then will be remodeled by Brooks Brothers and reopened in the spring.

Brooks will purchase the leases on the two locations, but not the inventories and fixtures or the Saltz business, said Stanley Rosensweig, chairman of Saltz and the managing partner of the local investors who own the long-established Washington clothier.

The three remaining Saltz stores--at White Flint and downtown on Connecticut Avenue and on G Street--will remain open. The G Street store will be remodeled and its women's wear section enlarged, added Rosensweig.

The talks between Saltz and Brooks began several months ago--before Brooks Brothers and its parent company, Garfinckel, Brooks Brothers, Miller & Rhodes Inc., were purchased by Allied Stores Co. of New York.

Allied has said it plans to continue the aggressive expansion of Brooks Brothers. A spokesman confirmed that Allied has "looked at the two locations and is interested in them."

Brooks Brothers is the most profitable of the former Garfinckel corporation operations and has been expanding both in the United States and overseas.

The Saltz business was purchased in 1977 by Rosensweig and Washington real estate developers Theodore Lerner and Albert (Sonny) Abramson.

Lerner and Abramson have several connections with Brooks Brothers. Lerner is one of the owners of Tysons Corner, where Brooks will take over the Saltz location. Lerner is putting up a major office complex downtown at Connecticut and L Streets where the Brooks Brothers store used to be located. When Brooks moved from that location to make way for Lerner's project, it moved into a building at 1840 L St. NW that is owned by Abramson.

Lerner and Abramson developed White Flint and shortly after buying the Saltz stores opened a branch in that Montgomery County shopping center. Bringing Saltz to White Flint to add an upper-end clothing store to that center's mix of merchants was one of the major reasons for purchasing the chain, Lerner said at that time.

But Rosensweig said recently the White Flint Saltz store drained some business away from the store in Chevy Chase, less than five miles away.

The Brooks Brothers and Saltz stores cater to similar traditionally-tailored customers, but Saltz, if anything, carries somewhat more expensive lines, such as Oxxford suits. Because of its cachet and merchandizing might, however, Brooks Brothers probably will be able to do more volume in the same store than Saltz was able to ring up.

Moving Brooks Brothers into the Chevy Chase neighborhood adds another major merchant to what is becoming the center of Washington fashion retailing. The established stores of Woodward & Lothrop and Lord & Taylor were joined by Neiman-Marcus a couple of years ago and several boutiques have opened adjacent to Neiman's in the Mazza Gallerie mall. The new Brooks location is a few doors away from Saks-Jandel, one of the premier Washington women's wear stores and across the street from the local branch of New York's Saks Fifth Avenue.

The two stores Brooks Brothers is taking over are relatively small for Brooks Brothers, with 13,000 square feet at Chevy Chase and 12,500 square feet at Tysons Corner.

Rosensweig declined to specify how much Brooks Brothers is paying to take over the two Saltz locations, but indicated Saltz will earn a significant profit by selling its leases to Brooks.