Joseph Kolshak, hired as chief operating officer of Midwest Airlines four months ago, has resigned from the Milwaukee-based carrier.
Midwest said Kolshak has left the company to pursue another opportunity but was not more specific.
Kolshak came to Midwest from Delta Air Lines, where he had been executive vice president of operations. A 20-year veteran of Delta, Kolshak joined Midwest shortly after the company was acquired by a TPG Capial, a Texas-based private equity group. Northwest Airlines also has a 47 percent stake in Midwest as TPG's minority partner.
"We thank Joe for his contributions in his brief time with us and wish him well in future endeavors," Midwest chairman and chief executive Timothy Hoeksema said in a statement.
Midwest is the second busiest carrier at Kansas City International Airport. Like most other airlines, Midwest has rediced flights in recent months in an effort to combat record fuel prices.