The K-B MacArthur Theater, a Washington institution for 36 years, closed indefinitely Sunday night after a showing of "Raiders of the Lost Ark." The theater, which has been run by the K-B Theater chain, will be taken over by the Washington Circle Theatre Corp. as of Sept. 1.

"We lost our lease," said Marvin Goldman, general manager of the Goldman family-owned five-theater K-B chain. "It expired and the landlord First FFSK Limited Partnership leased it to someone else--Circle. We had run it for 30 years and I think he wanted more money for it than we were willing to pay." Goldman declined to specify figures for the lease.

Ted Pedas, co-owner of Washington Circle Theatre Corp., confirmed that he has acquired a "long, long-term lease," for the 800-seat Art Deco theater, built in 1946 on the corner of U Street and MacArthur Boulevard NW.

"Our hopes for the theater are high," said Pedas. "We're talking about keeping the 70 mm screen the way it is, and we may add two other smaller screens. Maybe a few other elements, a place to eat . . . " Pedas also declined to discuss financial terms of the lease or renovation estimates, but said the new lease is "in excess of 25 years."

Pedas said he has contracted the architectural firm of Gunnar, Woodhouse Associates to study the theater and make recommendations for renovation. "We're going to go all the way with this because it is such a beautiful theater," Pedas said. "We have to put in a brand-new roof, a new ceiling, air conditioning and heating, brand-new seats and carpeting.

"We would like to open by Thanksgiving, for the holiday season," said Pedas, who did not specify plans for programming the three screens. "Our ideas change every day, of course. I can tell you it will be in keeping with what Circle theaters offer.

"We were going to try to keep it open with repertory while we were renovating, but we saw that it would be just too messy and an inconvenience to our patrons," Pedas said.