Congressional sources say the Pentagon will re-compete a $35 billion contract to build the Air Force’s fleet of new refueling tankers and pick a new winner by the end of the year.

Reps. Todd Tiahrt, R-Kan., and Norm Dicks, D-Wash., say the Office of the Secretary of Defense _ not the Air Force _ will oversee the competition between Boeing Co. and a team led by Northrop Grumman Corp.

The plan, which hands control to the Pentagon’s top acquisition chief and sets up a dedicated source-selection committee, indicates that senior civilians at the Defense Department have lost confidence in the Air Force’s ability to manage the contract.

The Government Accountability Office last month said Boeing might have won the contract had the service not made mistakes in evaluating the bids.