Evergreen International Airlines has filed a US lawsuit against The Boeing Company after it pulled a Dreamliner contract Evergreen had been counting on as a lucrative source of income for the next 20 years, awarding it to Atlas Air Inc instead.

“Boeing committed bad faith and breached its contractual promises to conduct its business fairly, impartially and in an ethical and proper manner,” Evergreen alleged in the complaint, filed in US District Court in Seattle. “Boeing’s bad faith and breach of contract have caused lost profits to Evergreen in excess of $175 million.”

Boeing selected Evergreen to operate the Dreamlifter, which transports parts for the 787 Dreamliner, in 2005 in a competitive bid process. At the time, the lawsuit says, Boeing told Evergreen it looked forward to “a long-term working together relationship with the LCF and 787 program,” which specified possible extensions through about 20 years.

Evergreen claims that in fact, Boeing started secretly negotiating with Atlas Air Inc., to transfer the contract to Atlas as compensation for delays in the 747-8 Freighters Atlas has on order.

“Boeing dropped Evergreen in favor of Atlas to avert the multimillion dollar disaster that was looming over the 747-8 program.”

Atlas has 12 747-8 Freighter on order, with options for another 14, Evergreen noted in the lawsuit. “A Boeing employee informed an Evergreen employee that Boeing’s liability for penalties to Atlas approached $1 billion. By at least October 2009, Atlas had made a claim with Boeing for refunds resulting from Boeing’s failure to meet delivery guarantees toAtlas.”

While either party could cancel the contract, “the right was subject to both and express and implied covenant of good faith and fair dealing,” Evergreen said in the complaint.