United Airlines will codeshare with Star Alliance partner Swiss on its flights between Zurich and Moscow.
The codeshare will replace United's current agreement with BMI on the latter's flights between London-Heathrow and Moscow, according to a filing with the US Department of Transportation (DOT). The BMI codeshare ends on 31 May.
BMI was bought by International Airlines Group (IAG), which is the parent of Oneworld carrier British Airways, in April.
United passengers travelling to Moscow from the US will either be routed on Swiss's flights via Zurich or on the carrier's own flight to the Russian city from Washington-Dulles on a 208-seat Boeing 767-300ER.
United applied to downgrade its Moscow flight to seasonal status with the DOT in April. The airline would operate the flight only in the third quarter if its application were approved, it told Flightglobal at the time.