United Airlines has signed a 10-year extension to the lease for its maintenance facility with the San Francisco Airport Commission.
The 52.7ha (130 acre) maintenance operations centre at San Francisco International airport maintains aircraft airframes, engines and components, as well as makes cabin modifications.
"United's investment underscores our commitment to San Francisco, the maintenance operations centre and its role in supporting the industry's premier trans-Pacific hub," says Greg Hart, senior vice-president of technical operations at United, in a statement.
The Chicago-based carrier conducts maintenance on its Boeing 747-400 fleet as well as other aircraft types in San Francisco.
United has maintenance facilities at Chicago O'Hare, Cleveland, Denver, Houston Intercontinental and Hobby, Los Angeles and Orlando, and it is building widebody hangars at Newark and Washington Dulles that will be complete by the end of the year.