Kennedy Center officials announced yesterday a six-week summer season of chamber opera, beginning July 10 in the Terrace Theater with a double bill of Mozart and Weber.

The five works to be performed, which also include operas by Donizetti, Offenbach and contemporary composer Dominick Argento, will be unfamiliar to most audiences. Several have not been recorded yet.

The venture is in conjunction with the Washington Opera, and was described as a "first season" of the Kennedy Center Summer Opera. "There may or may not be a second reason, depending on the response at the box office," said Center's Executive Director Martin Feinstein, who will direct Summer Opera.

Until now, virtually all opera at the Center has been performed in the Opera House by visiting companies. But this season's opening of the 475-seat Terrace Theater "makes it possible for us to present the kind of small ensemble that could not be done in the Opera House," Feinstein said.

The budget for the summer season is $500,000, including $200,000 from the Center's coporate fund and a grant of $20,000 from the National Opera Institute. Feinstein added that generous concessions were made by labor unions at the Center.

John Mauceri will be music director and principal conductor. The Washington Opera's artistic director, Francis Rizzo, will carry the title Dramaturg. And the Opera's Managing Director Gary Fifield will fill that role with the Summer Opera.

The opening double bill will consist of two short operas known almost entirely for their famous overtures, Mozart's "The Impresario" and Weber's "Abu Hassan." New translation and adaptations of the works are being written by Broadway playwright Hugh Wheeler, who collaborated with Stephen Sondheim on "A Little Night Music" and with Leonard Bernstein on the revised "Candide." There will be 11 performances.

The next work will be Argento's one-act "Postcard From Morocco," opening the night after the double bill. It will be repeated five times. Next will be "Christopher Columbus," a pastiche of music from Offenbach's least-known works. "At first I didn't like the idea of doing a work that was not authentic, but we were all won over when we heard it," Feinstein said. It opens July 31 and will receive 12 performances.

Last will be a little-known work by Donizetti, "Il Furioso all" Isola di San Domingo." It was recently revived at the Spoleto Festival USA and will open here Aug. 7 for six performances.

The operas will be cast with young singers mostly on the rolls of the New York City Opera and the Metropolitan.