Boeing fears that delivery of its 787 Dreamliner could be delayed until early 2011.
The next-generation aircraft has already been delayed by two years.
According to Reuters, the plane manufacturer has not yet taken the decision on whether to move the first delivery of the 787, but tests have raised concerns.
Scott Fancher, general manager of the 787 Dreamliner program, said: "We've seen some issues recently that have pushed our margins a bit.
"We wanted to give a little bit of a cautionary note that things could push into the first part of next year," he told reporters.
The issues concern instrument configuration and inspection work, he said.
Boeing plans to display a Dreamliner at Farnborough air show next week.
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