American Airlines has withdrawn its opposition to an $8.5 billion planned expansion at Chicago’s O’Hare International Airport after the city agreed to expedite construction of three gates that all airlines can use.

American Airlines announced its opposition last month, citing a provision that the Fort Worth, Texas-based airline said gave more gates to Chicago-based United Airlines. On Thursday, Chicago Mayor Rahm Emanuel’s office said the city is committed to working with American to expedite the construction of three common gates.

American CEO Doug Parker says the mayor and his team “worked tirelessly and creatively to structure an agreement that keeps competition thriving at O’Hare.” United CEO Oscar Munoz says the agreement gives O’Hare a competitive edge and ensures competition thrives between airlines.

The eight-year plan would be the single largest and most expensive terminal revamp in the airport’s history.

(AP)