About 1,000 pilots, flight attendants and mechanics are covered by the contracts, which took nearly a year to reach and brought the unions to the brink of a strike.
Mesaba said it needed the labor deals to continue handling regional flying for Northwest Airlines Corp., which also is operating in bankruptcy. Mesaba earlier got permission from a bankruptcy judge to impose cuts amounting to 17.5 percent of pay and benefits on the unions, but held off as the two sides continued bargaining.
Union leaders said they weren't happy with the deal, but that it was necessary to keep Mesaba flying and preserve jobs for their members.
"I wouldn't say it's a victory," said Tom Wychor, head of the Air Line Pilots Association unit at Mesaba. "We gave concessions in order to save the airline."
The pilots accepted the agreement with roughly 68 percent of the vote. Eighty-two percent of flight attendants voting approved it, and 65 percent of mechanics did.
Starting Friday, flight attendants' wages will drop 2.7 percent; pilots between 5 and 5.5 percent, depending on what kind of plane they fly. Mechanics will take an 8.5 percent pay cut.
The average Mesaba flight attendant was making about $24,000 a year, pilots were averaging about $45,000 and mechanics with five years' experience were earning about $37,000.
Wychor said the airline came "extremely close" to liquidating. "Personally, I was figuring out how to afford Christmas presents," he said.
Mesaba's management issued a statement saying the agreements were necessary to emerge from bankruptcy.
"The pilots, flight attendants, and mechanics along with every single Mesaba employee, are making a considerable sacrifice to ensure the survival of this company and I am confident we will see brighter days ahead," John Spanjers, the airline's president and chief operating officer, said in the statement.
Northwest issued a statement saying it was pleased with the agreements.
Mesaba flies to 88 cities, funneling passengers into Northwest hubs in Detroit, Minneapolis and Memphis. Its fleet once numbered about 100 planes, including regional jets, but Northwest has reduced that to 49 prop-driven Saab aircraft.