After months of intense deliberations, Sun Country Airlines and the union representing its 250 pilots have reached a tentative contract agreement, sources said Saturday.

Terms of the potential accord were not immediately available and approval of any contract would require ratification by members of the Air Line Pilots Association (ALPA). Economic issues, including pay, are at the heart of the dispute.

The tentative agreement was described as "comprehensive."

The pact was reached Friday night in Washington, where members of ALPA and the airline's management and owners met with a federal mediator.

When contacted in Washington on Saturday, Sun Country Chairman Marty Davis said he had no comment.

ALPA spokesman Rusty Ayers was not immediately available for comment.

The tentative agreement follows five years of on-and-off negotiations, which became contentious earlier this year.

In February, ALPA members voted to authorize a strike, although no date was set. In May, Davis warned the pilots' union that the airline faced a "downsizing" if a labor agreement was not reached.

The issue was sensitive enough that the Metropolitan Airports Commission put a $35 million expansion plan on hold for Terminal 2, where Sun Country has its gates.

Mendota Heights-based Sun Country has a fleet of 20 Boeing 737s and is the third largest operator at Minneapolis-St. Paul International Airport behind Delta Air Lines and Spirit Airlines.