The Air Force says it mistakenly sent Boeing and EADS North America information about each other's aerial refueling tanker bids.

Air Force Col. Les Kodlick told The Seattle Times Friday, a clerical error earlier this month was to blame for the mixup in which a "limited amount of identical source selection information was sent to both competitors about the other competitor's offer."

Boeing is offering a military version of its 767 in competition with European defense contractor EADS, which will use an Airbus A330.

The Pentagon is expected to award a $35 billion contract for 179 planes early next year. Replacing the fleet of aging tankers could be worth up to $100 billion.

Kodlick says both companies noticed the problem and contacted the Air Force.