The deal comes after years of unsuccessful contract talks and allegations made by the pilots union that Allegiant failed to abide by a July 2014 federal court injunction that directed the low-cost carrier to restore the pilots' benefits and work rule protections to levels negotiated previously.

The tentative agreement must be voted on and ratified by Allegiant Air pilots, who were represented by the International Brotherhood of Teamsters, and the results are expected in late July, the company said.

Last year, the air pilots threatened to go on a strike but they were blocked by a U.S. court after Allegiant sued the pilots' union saying they had violated the Railway Labor Act by moving to strike before the parties had exerted every effort to settle their disputes.

Later the company said it would raise its pilots' pay by 5-7 percent per hour effective May 1, 2015 and that the Federal Aviation Administration (FAA) had stepped up its surveillance of labor disputes at the low-cost airline operator.

(Reporting by Shivam Srivastava in Bengaluru; Editing by Gopakumar Warrier)