Financially ailing United Press International has signed a lease and will take up new residence in the Wire Building at 1000 Vermont Ave. NW--the site of Sholl's New Cafeteria--sometime in July.

According to an internal memo, the news wire service will lease four floors of the building and rename it the UPI World Headquarters Building. UPI recently announced that it would move its main news offices from New York to Washington and its executive offices to Nashville.

Editorial sources within UPI confirmed the move. Roughly 100 editorial personnel would be involved in the Washington move.

UPI sources said the service will relocate its Washington bureau from the National Press Building to the Vermont Avenue offices by June 30.

UPI, which was formerly owned by E. W. Scripps Co., was purchased by a group of Nashville investors in 1982. As part of the privately held Media News Corp., the company is not required to reveal earnings. The firm is reported to be losing money, however, a company spokeswoman said the service is positioned to break into the black by mid-1984.

UPI also expects to be transmitting its news by satellite instead of over dedicated land telephone lines to its estimated 5,400 domestic clients. The satellite switchover is expected to save UPI more than $5 million, which would make it profitable.