Under pressure from Sen. John McCain, the U.S. Air Force on Wednesday withdrew a request for information from companies interested in a multibillion-dollar competition to replace KC-135 aerial refueling tankers.

The Air Force had quietly issued the “request for information” last Friday, surprising lawmakers and even some senior defense officials, since it appeared to prejudge the outcome of a comprehensive review of alternatives for modernizing the tanker fleet, which is still being finalized.

The Air Force had defended the decision for several days before changing its mind and withdrawing the document late on Wednesday, after McCain, an Arizona Republican and powerful member of the Senate Armed Services Committee, sent a terse letter to Defense Secretary Donald Rumsfeld on Wednesday.

McCain told Rumsfeld the Air Force action flew in the face of efforts to determine the best strategy for modernizing the fleet of aging KC-135 tankers used to refuel fighter jets and other aircraft in mid-flight, said one Senate aide familiar with the letter.

McCain said he would do all he could to see the document revoked if the service failed to do so, the aide said.

“It was a bit premature,” said Air Force Col. Chris Geisel as he announced the decision to withdraw the document.

He said the Air Force rescinded the request since it might need to issue another one after completion of a two-month review of a long-awaited Rand Corp. analysis on tankers.

Geisel said the Air Force would decide whether to issue a new request for information from industry after the so-called “sufficiency review” of the Rand report — by the Pentagon’s office of program evaluation and the independent Institute for Defense Analyses — was completed in October.

The Senate aide said the Air Force still did not understand that lawmakers had special concerns about the tanker modernization program after the conviction of a former Air Force official for inappropriate ties to Boeing Co.

He noted an ill-fated earlier tanker program had also begun with a hasty “request for information” rather than a formal “analysis of the alternatives” as required by federal law.

Congress last year killed a $23.5 billion proposed deal between the Air Force and Chicago-based Boeing after ex-Air Force official Darleen Druyun admitted she accepted an inflated price as “a parting gift” to Boeing before taking a $250,000-a-year job with the company.

Druyun is serving a 9-month prison term for violating federal conflict of interest laws.

A series of government and congressional reports concluded the Air Force inappropriately rushed into the tanker deal and overstated the degree of corrosion on the existing tankers.

Those reports and an investigations spearheaded by McCain prompted the Pentagon to order a thorough review of all the options before any decisions were made on the tanker fleet.