Spirit AeroSystems said there is "substantial doubt about the company's ability to continue as a going concern" though Boeing and Airbus are planning to acquire portions of the parts maker.

Spirit AeroSystems, a key Boeing supplier, is temporarily laying off workers on its 737 production line to manage an inventory surplus, the company said Friday.

A financial analyst with The Teal Group, Bruce McClelland, said, Boeing is controlling the purse strings on decisions as we move even closer to the expected merger with Spirit AeroSystems this summer.