(Reuters) -Boeing ( BA ) has offered to acquire Spirit AeroSystems Holdings ( SPR ) in a deal funded mostly by stock that values its key supplier at about $35 per share, Bloomberg News reported on Monday, citing people familiar with the matter.

This offer represents a premium of nearly 6% over Spirit's stock closing price of $33.07 on Monday and a 22.4% upside to its closing price on Feb. 29, the day before Boeing's ( BA ) takeover talks became public.

Boeing ( BA ) switched its offer from an all-cash one and while the final terms of the latest offer are still being discussed, it could include a small amount of cash, Bloomberg reported, adding the deal is expected to be announced within a matter of days.

Spirit said it remains "focused on providing the best quality products for our customers". Boeing ( BA ) did not immediately respond to a Reuters request for comment.

Boeing ( BA ) initiated talks earlier this year to buy back the Wichita, Kansas-based supplier it spun off in 2005, seeking to stabilize a key part of the supply chain for its strongest-selling jet following a mid-air blow out on a new 737 MAX in January.

Boeing ( BA ) has said it is buying back Spirit to secure safety and quality in its plants, after blaming Spirit for sending incomplete or faulty parts to its factories.

However, talks hit a stumbling block over Spirit's work for Airbus, with the European group threatening to block any deal that involved Boeing ( BA ) building parts for its newest models.

The deal will require Spirit to spin off some of its manufacturing plants to Airbus, Bloomberg reported.

Reuters earlier reported that Boeing ( BA ) and Airbus have broadly succeeded in dividing Spirit's programs into work that Boeing ( BA ) will take back, along with work that the Airbus will take.

Spirit posted a net loss of $617 million and burned through $444 million in the first quarter, far more than analysts had expected.