CHICAGO » United Airlines pilots have ratified a contract extension that includes pay raises and gives the company more certainty about labor costs.

The Air Line Pilots Association said today that 79 percent of pilots who voted agreed to add two years to their contract, making it run through January 2019.

United has about 12,000 pilots.

Details of the extension aren’t being released, but the union says it puts the pilots’ compensation at the top of the industry. United says it will create stability for the airline and the pilots.

United struggled to combine workforces after its 2010 merger with Continental. New management that took over last September has vowed to improve labor relations.

In late afternoon trading, shares of United Continental Holdings Inc. climbed $1.41, or 3.1 percent, to $46.74.