The company signed an out-of-court settlement with the two remaining defendants in its 1979 suit alleging a conspiracy to bar it from the interstate telephone market, spokesmen for the parties said. The agreement, with United States Telephone Assn. and United Telecommunications Inc., barred disclosure of the terms, said Gary Tobin, an MCI spokesman. MCI had earlier settled out of court with all of the other defendants, including AT&T, the now-divested Bell operating companies and 10 smaller enterprises. Through the previous settlements, MCI earned more than $200 million in cash and services, Tobin said.