Frustrated by their wages and work rules, Sun Country Airlines mechanics voted to unionize.

Sun Country's aircraft maintenance mechanics and related employees voted to elect the Aircraft Mechanics Fraternal Association (AMFA) as their collective bargaining agent, the National Mediation Board announced Thursday. The vote was 75-30 for union representation of 131 eligible employees.

Sun Country said it supported "the employees' right to choose whether they wanted to be represented by a union, and we respect the outcome of this vote."

In a statement, the airline added, "We appreciate everything our technicians do to support the safe operations and success of our airline, and we value our discussions during this process about how to make Sun Country an even better place to work."

Sun Country has lost one-third of its mechanics and related technicians over the past year because of inadequate pay and work rules, said Bret Oestreich, AMFA's national president. Many joined Delta Air Lines, he said.

"Pay is probably the No. 1 thing for them," Oestreich said. "The work rules keep changing and it's like the wild, wild west and they're fed up."

Wages start around $28 an hour and range up to about $44 an hour for Sun Country mechanics and related employees versus around $35 to nearly $60 an hour at Delta, according to AMFA data. Delta has the biggest flight operation at Minneapolis-St. Paul International Airport.

Earlier this winter, mechanics at Sun Country submitted signed authorization for representation cards from nearly 75% of its workgroup to AMFA, requesting that they file for a representation election with the national board on behalf of their workgroup.

The union also represents mechanics at Alaska Airlines, Horizon Air and Southwest Airlines. A unionization effort also is in the works among mechanics at Spirit Airlines, Oestreich said.

Sun Country technicians had been non-union since the carrier launched in 1983.

Sun Country's pilots union recently came to an agreement with the carrier that included wages considered competitive industrywide, including with Atlanta-based Delta. Flight attendants and dispatchers also are unionized at Sun Country.

Meanwhile, Delta flight attendants are in the midst of a unionization drive.

The unionization trend has been on the rise in Minnesota. With new construction projects and fresh organizing, state union membership in 2021 grew to its highest level in 14 years, seemingly bucking a national trend that has seen memberships bouncing close to 40-year lows.

The number of Minnesota workers belonging to a union rose from 398,000 to 416,000. That's about 16% of all workers in the state, according to data released by the U.S. Labor Department.