Boeing welcomed the Pentagon's decision on Wednesday to reopen the competition for the US Air Force's next generation of mid-air refuelling tankers, which had originally been awarded to rivals Northrop Grumman and EADS, according to dpa. In March, Northrop and and the European defence firm EADS had won the 35-billion-dollar contract over rival Boeing to build 179 aerial refuellers, but the Pentagon said Wednesday that it will revive the bidding after a congressional agency found flaws in the the process. "We welcome the decision by Defense Secretary Robert Gates not to proceed with the contract award to Northrop Grumman/EADS and to reopen the KC-X tanker competition," Boeing said in a statement. On June 18, the Government Accountability Office (GAO) upheld a formal Boeing protest that the Air Force overlooked several key aspects of the Boeing proposal, and the watchdog agency urged the Pentagon to hold a new competition. Gates said that the competing defence firms must now submit revised proposals. "It's encouraging that the Defense Department intends to take steps to ensure a fair and open competition," Boeing said.