Simplify the following text for a Grade 11 native English-speaking person.
Original: With its new system of transpacific flights established , Northwest began to advertise itself as the Northwest Orient Airlines , although its registered corporate name remained `` Northwest Airlines '' .
Simplified: Northwest Airlines ' regional flights are operated under the name Northwest Airlink by Mesaba Airlines , Pinnacle Airlines , and Compass Airlines . Northwest Airlines is currently a minority owner of Midwest Airlines , holding a 40 % stake in the company .