Boeing released more details of its potential proposal in the competition to replace the U.S. Air Force’s aging tanker refueling fleet.

Boeing said Monday it is prepared to offer a tanker based on its commercial 767, as it did in an earlier competition, or its larger 777.

“Boeing is ready to deliver maximum capability at the lowest cost,” Boeing KC-X director and program manager Rick Lemaster said in a statement.

Boeing conducted a briefing at the Air Force Association’s 2009 Air & Space Conference and Technology Exposition outside Washington.

Boeing and Northrop Grumman are in competition for a $35 billion deal for 179 aerial refueling tankers. The Pentagon is working on a draft request for proposal for the competition but has not set a date for its release.