MILWAUKEE - Midwest Airlines announced Sunday the initiation of service aboard 50-seat regional jets between Milwaukee and Columbus, Ohio, and on select flights between Milwaukee and both Minneapolis/St. Paul and Philadelphia.

Midwest said SkyWest Airlines, flying as Midwest Connect, is eventually to use a minimum of 15 and up to 25 of the Canadair jets under a five-year pact between the firms announced several months ago.

The agreement calls for the St. George, Utah, based airline to provide aircraft, flight crews and maintenance services for the jets, while Midwest oversees route planning, scheduling, marketing and sales.

"Today's launch of the Midwest Connect 50-seat jet service is just the beginning of our efforts to improve service across our network and 'right size' Midwest Airlines in order to enhance our financial performance," said Scott R. Dickson, Midwest Airlines senior vice president and chief marketing officer.

"These jets play a key role in helping us expand our reach into new markets, upgrade certain markets to larger aircraft and to ultimately add more flights in key markets." The aircraft will also be used for new service between Kansas City and Columbus and upgraded service on three of four daily flights between Milwaukee and Pittsburgh starting May 1. Beginning June 1, the 50-seat jets will be used for new service between Milwaukee and Raleigh/Durham, N.C., and upgraded service on all flights between Milwaukee and Baltimore/Washington.

Dickson said announcements about further deployment of the aircraft are expected to be made in upcoming weeks.