UPDATE 2-Air Force hasn't asked GAO to review tanker ruling

(Adds byline, Air Force, company and analyst comments)

By Andrea Shalal-Esa

WASHINGTON, July 1 (Reuters) - The U.S. Air Force said on Tuesday it had not asked the Government Accountability Office to reconsider its June 18 decision upholding Boeing Co's (BA.N) protest against a $35 billion contract awarded to Northrop Grumman Corp (NOC.N) and EADS (EAD.PA).

"The Air Force has not requested reconsideration by the GAO," said Air Force spokesman Lt. Col. Karen Platt.

Under federal rules, the service has 10 days to ask the GAO to reconsider its decision "after the basis of reconsideration is known or should have been known, whichever is earlier."

The Air Force did not file any request during the initial 10-day period after the decision, but Platt said its lawyers were continuing to review the ruling and could still request reconsideration within 10 days of discovering the basis for such a request.

"We are still reviewing the GAO decision ... and we are still identifying the best way forward," she said. "Just because we have not gone to the GAO doesn't mean we don't have that right in the future. It's not a done deal."

The Air Force technically has 60 days to respond to the GAO ruling, although defense officials and analysts say they expect a decision much sooner -- possibly within two weeks.

Virginia-based defense analyst Jim McAleese said the Air Force's failure to file an initial appeal made it likely that it would follow the GAO's recommendation to seek new proposals and rerun the competition for new aerial refueling aircraft.