A number of issues are still to be resolved before the sale of Bombardier's Northern Ireland operations can be completed.
US firm Spirit AeroSystems agreed to buy the business in October 2019.
On Tuesday, Spirit's chief executive said the firm was talking to Bombardier about "the conditions needed for closure of the deal".
Tom Gentile said he continued to see the "long-term strategic value" of the purchase.
Spirit, which is based in Kansas, is a major supplier to Boeing.
The company wants to do more work for Airbus and buying Bombardier's Northern Ireland operation is part of that strategy.
The wings for the Airbus A220 are made at Bombardier Belfast's plant.
In a briefing with financial analysts, Mr Gentile would not be drawn about what conditions still need to be satisfied.
He was also asked if Spirit was seeking a lower price after Bombardier recently lost a planned Airbus contract for engine covers.
Mr Gentile said they were monitoring the situation and talking to Bombardier about possible impacts.
Spirit's purchase of the Bombardier assets was originally planned to be completed in the first half of this year.
The process has a "long-stop date" or deadline of 31 October.