The accord, signed in the central city of Deblin in the presence of Polish Prime Minister Leszek Miller, involves a compensatory investment programme of over 12 billion dollars, according to a statement from the economy ministry and Lockheed Martin reported by the PAP news agency.

"It's the contract of the century," Defence Minister Jerzy Szmajdzinski said at the signing ceremony.

He described it as a "strengthening of strategic links with the US."

Poland needs the planes to come up to the standards of the NATO military alliance which it joined in 1999.

The deal is eastern Europe's biggest defence procurement yet and followed a tough competition between US and European defence giants.

Lockheed Martin beat out European rivals last December, knocking British-Swedish consortium BAE Systems-SAAB with its Jas-39 Gripen and France's Dassault Aviation with its Mirage 2000-5 out of the race, to win the contract for the new fighter fleet.

The deal drew criticism from EU countries, who thought a member-in-waiting should have given its business to an EU company.

SPACE.WIRE