A Boeing 787-8 was diverted to Seattle on Tuesday afternoon due to an mechanical problem.
United flilght 139 was enroute from Denver to Tokyo when there was an indication of a problem with an oil filter, United officials said.
The aircraft landed normally at Sea-Tac at about 4:10 p.m. and United was working ot accommodate the passengers.
No one was injured.
The FAA will investigate.