"We believe that a single integrated trans-Atlantic market place best serves the collective security interests of the United States and our European allies," David Potts, Lockheed Martin International Senior Director told participants in an international conference in Sofia on business opportunities created by NATO enlargement.

Potts said that in building such a market would help NATO allies deal with "issues of interoperability and gaps in capabilities between the U.S. and Europe."

"It is simply not possible for anyone single nation, including the United States to rely solely on its own resources, on its own industry for its security, " Potts said.

He said the importance of defense industry integration within NATO reached far beyond political disagreements among the allies as those on Iraq.

"Our relationships are too enduring and too important to buffeted by short-term gusts of political discord," Potts said.

He said the U.S. does not oppose creation of a common European defense industry market but added it should be opened to outside competition.