United Airlines pilots have voted to approve a new contract valued at $10.2 billion, marking  the largest contract ever struck for any airline in history.

The four-year deal offers a cumulative increase in total compensation which will rise as high as 40.2%. In the vote, 82% of the 16,000 pilots at United voted for the contract with 97% of pilots casting their ballots according to the Airline Pilots Association, International Union (ALPA).

ALPA noted the contract will contain “an industry-leading” increase in salary as well as “quality of work-life and work rule improvements, sick leave and vacation improvements, and an increase in retirement benefits.”

The contract became effective on Friday, and will run through September 30th, 2027.

With the finalization of the deal, United joins with American Airlines (AAL) and Delta Airlines (DAL) in finalizing new contracts with their pilots unions this year. Southwest Airlines (LUV) is the only remaining airline of the four largest carriers in the United States which has not yet inked a deal with its pilot’s union.

Shares of United Airlines have held steady on the news.