Frontier Airlines, a division of Indianapolis-based Republic Airways Holdings Inc., plans to cut 213 jobs at Mitchell International Airport in Milwaukee.

Frontier said in a formal notice Friday to the Wisconsin Department of Workforce Development that the positions will be eliminated permanently in November.

Republic, which acquired Frontier out of bankruptcy in 2009, has been struggling to return the Denver-based airline to profitability.

Shares of Republic have been in a freefall since it posted a $15 million loss for its fiscal second quarter on Aug. 2, mainly due to trouble experienced by Frontier.

The company’s stock opened Monday at $2.91 a share, down nearly 50 percent in the past three months and nearly 70 percent off its 52-week high.

Frontier said last week it plans to cut nearly a third of its 67 flights from Milwaukee in November in a move to end routes that are losing money.

The Milwaukee Journal Sentinel said Frontier's service to six cities will be grounded: Green Bay and Madison, Wis.; Dayton and Cleveland, Ohio; Des Moines, Iowa; and Minneapolis.