The much-anticipated Broadway production of the British musical "Chess" has been postponed indefinitely because of "insurmountable scheduling difficulties," Gerald Schoenfeld, president of the Shubert Organization, said in a telephone interview Thursday from his New York office. The Tim Rice musical, about a match between an American and a Soviet chess champion, has been running in London since May, 1986, and was set to start rehearsals at New York's Imperial Theater in early February. "We haven't reached any conclusions (about rescheduling). We're dealing with people in England, Sweden. . .," said Tyler Gatchell, executive producer and general manager of the production, in a telephone conversation from New York. "There just wasn't enough time to put it on this season."