UPDATE 1-Pentagon eyes Sept for next step in aerial tanker

* Terms of tanker competition may not surface until Sept

* No final decision yet on timing of request for proposals

WASHINGTON, July 15 (Reuters) - The Pentagon may not
release until September the details of its next competition for
the long-delayed replacement of aging Air Force aerial tankers,
a Pentagon spokesman said on Wednesday.

The Defense Department last year canceled a $35 billion,
179-plane contract it had awarded to Northrop Grumman Corp
(NOC.N) and its European partner, EADS (EAD.PA), after
government auditors upheld a challenge from losing bidder
Boeing Co (BA.N).

The Pentagon recently said it expected to issue in
mid-summer a draft request for proposals (RFP), the detailed
document that outlines the terms of the competition to choose a
winning bidder for the project.

"No final decision has been made on this yet. I think this
is something that is still being worked," the spokesman told
reporters. "We may be looking at August, we may be looking at
September."

"And frankly, this may go into the fall because we want to
make darn certain we get it right. And so everybody is double
and triple checking the proposed way ahead to make sure that it
is bullet proof," the spokesman added.

The United States must act soon to replace its aging fleet
of 415 KC-135 refueling aircraft, which are nearly 50 years old
on average. The planes are used as flying gasoline stations to
help get fighter aircraft and other warplanes to distant
battlefields without having to land.

(Reporting by David Morgan, writing by Julie Vorman)