BOEING Co said yesterday it may protest any changes to the United States Air Force's US$35-billion aerial tanker tender, which would further delay an order that's being rerun after it was awarded to Northrop Grumman Corp using Airbus planes.

Boeing doesn't "want to rule out anything" in terms of how far it might take objections should there be unfavorable modifications to contest terms from the US Air Force, the company's defense chief, Jim Albaugh, said at a briefing in London.

Boeing, sole supplier of the air force's aerial-refueling tankers for half a century, submitted a bid based on a version of its 767 jetliner, Bloomberg News said. The air force on February 29 instead picked Los Angeles-based Northrop's entry, which used a bigger, reconfigured A330 plane made by Airbus, a unit of European Aerospace, Defence and Space Co and Boeing's larger competitor in commercial planes. The Department of Defense last week said it would reopen aspects of the bidding to make sure the air force decision was fair.

"We don't see a need for a bigger aircraft," said John Lockard, the defense unit's chief operating officer, said at a briefing yesterday at the Farnborough International Air Show outside London. "Obviously if they choose that they need to have some other capability, we'll address it."

The Pentagon reopened the tanker contest to fresh bids after the Government Accountability Office last month said the air force made mistakes assessing the bids.