Boeing said Wednesday its employees acted in an "exemplary" fashion in handling EADS data erroneously sent by the US Air Force to its rival in bidding for a big aerial refueling tanker contract.

"When faced with the unusual and delicate situation of receiving a disc with our competitor's sensitive data recently, the two Boeing employees who received the disc acted in an exemplary fashion to safeguard and return it to the customer without gaining access to its contents," Bill Barksdale, spokesman for Boeing's defense arm, said in a statement.

Two air force officials were removed last month from the refueling tanker program after Boeing and the European Aeronautic Defence and Space Company, parent of France-based aircraft maker Airbus, received each other's data.

The Pentagon said that one of the two companies, which it did not name, had opened the data.

"As a defense contractor, Boeing understands that our government customers place great trust in us to handle sensitive information with extreme care, and we train our employees in the proper procedures to keep that information safe and secure," Barksdale said.

He said the question of whether the incident will have an impact on the competition for the 35-billion-dollar contract was difficult to answer.

"We're still in the process of reviewing the situation and its implications with the US Air Force," Barksdale said in a statement.

The US Air Force said in early December it had tried to correct the mix-up of technical analyses by sending to each company the other's information and allowing them "equal access" to review it.

The fix came after the Air Force reportedly learned that EADS had opened a computer file with information about the bid of its rival, Boeing.

The EADS revelation was first reported by The New York Times, with an official saying forensic investigators that inspected computers from both companies concluded that an EADS worker had opened a file with details of how Boeing's proposal performed in a technical evaluation.

The chief executive of EADS North America, Sean O'Keefe, has said his firm's employees had not read files with data about Boeing's proposal.

Separately, EADS North America announced Wednesday that it is seeking bids for the design and construction of a plant in Mobile, Alabama, where its proposed aerial refueling tanker would be militarized for the air force.

"The KC-45 will create or support 48,000 American jobs across the country, and create more than 1,500 direct positions in Mobile," EADS North America said in a statement.

A final decision on the long-fought contract to replace 179 aerial refueling tankers in an aging Boeing-built fleet was delayed last month to early next year. No date has been set.

The document foul-up is the latest setback for the politically charged tanker contest, which has been marked by scandal and intense lobbying in Congress.

In 2008, EADS in partnership with Northrop Grumman won the contract for the tankers, but the deal was canceled after a successful Boeing appeal to the investigative arm of Congress.

Northrop dropped out in the latest contest.

US Air Force commanders see the planned KC-X aircraft as crucial to bolstering American air power and are anxious to replace the older Boeing KC-135 Stratotankers that date back to the 1950s.