Republic Airways Holdings Inc., which bought Frontier Airlines and Midwest Airlines last year, says it will move all of its executives to its base in Indianapolis as it further consolidates its two new airlines.

When they were independent carriers, Frontier was based in Denver and Midwest was based in Milwaukee.

Republic spokesman Carlos Bertolini said roughly 3,000 workers will continue to be based in Denver, mostly flight crews and reservations workers. About 1,200 work in Indianapolis and roughly 1,500 will work in Milwaukee, once all the transitions are done, he said. Employment in Milwaukee is actually rising because Republic is shifting some maintenance work to that city.

Republic's purchases last year of Frontier and Midwest turned it into a hodgepodge of brands. Republic has long done feeder flying for hire by big carriers on its other operations, which include Chautauqua Airlines and Shuttle America. By adding Midwest and Frontier, it got into the business of competing for its own passengers instead of taking those fed to it by other airlines.

Bertolini said Republic still plans to keep the Midwest name. However, all Midwest flying has been done by Republic crews since late last year.

Republic also said it will move to a common system for reservations on Frontier and Midwest, and will integrate their frequent-flier programs. Bertolini said frequent fliers shouldn't worry about losing their miles.

"We're looking at trying to make enhancements, not move in the other direction," he said.

Republic also said former Frontier CEO Sean Menke is resigning. Menke guided Denver-based Frontier through bankruptcy protection. When Republic bought Frontier out of bankruptcy in October, it kept Menke, naming him chief marketing officer.

Republic said Menke will stay through the end of March. The company says Menke "made the personal decision" to resign. Bertolini said he couldn't elaborate on Menke's reason for leaving, and said Menke wouldn't be available for interviews.