The Chicago-based aerospace giant lost the contract to a team formed by European Aeronautic, Defense & Space Co., the parent of Airbus, and Northrop Grumman, The Seattle Times reported Saturday.
Boeing executives that met with Air Force officials Friday said they emerged with "significant concerns" about the contract awarding process.
"What is clear now is that reports claiming that the Airbus offering won by a wide margin could not be more inaccurate," said Mark McGraw, Boeing vice president and program manager of the KC-767 tanker.
Boeing said it is considering filing a protest, the newspaper reported.
"Our plan now is to work through the weekend to come to a decision on our course of action early next week," McGraw said. "It will be a very rigorous and deliberative process to ensure we're balancing the needs of the warfighter with our desire to be treated fairly."