"This event is the expression of the Polish-American partnership," Polish Prime Minister Leszek Miller, one of Washington's staunchest backers in its Iraq campaign, said after Warsaw signed the contract for the 48 Lockheed Martin planes.

The significance of the nationally televised event was echoed by Washington, whose ambassador to Poland Christopher Hill said no less than "a marriage" had taken place with the signature.

US General Tome Walters, after signing the accords for the United States, said: "What gives me the most pleasure is the strategic relationship that will now grow deeper and broader between the United States and Poland."

The planes are needed to bring Poland's military up to the standards of NATO, which it joined in 1999. Walters said that with their purchase Poland "had made a strategic decision that's going to shape your national security for the next 30 years."

Under the terms of the agreement, the biggest defence procurement deal in Eastern Europe to date, the first 16 planes will be delivered to Poland in 2006 and their payment will be due from 2010.

However most of the attention at the ceremony and subsequent news conference in Deblin, central Poland, was focused on the US investment package that went with it, which Hill said was the biggest that had ever been signed.

"This is the biggest offset agreement that's ever been signed," the ambassador said.

"This gives us a real possibility to move ahead in our economic relations."

The deal was the fruit of long wrangling over the value of compensatory, or offset, investments in Poland.

Under Polish law the cost of procurement contracts must be offset by an investment package.

"The nominal value of the compensatory investments (offset) comes to 7.5 billion dollars and its real value reaches the level of 12 billion dollars," Economy and Works Minister Jerzy Hausner said after the deal was signed.

Warsaw came to the figure of 12 billion dollars by using a complicated system of multipliers, which take into account the domino effect of initial investments.

Lockheed Martin snared the contract in December, beating bids from British-Swedish consortium BAE Systems-SAAB with its Jas-39 Gripen and France's Dassault Aviation with its Mirage 2000-5.

The deal drew criticism from European Union countries, who thought a member-in-waiting should have given its business to an EU company. The choice threw the spotlight on a conflict in loyalties for Poland, as it cuddles up to the United States while preparing to join the EU.

Poland and nine other candidates on Wednesday signed accession treaties to the 15-state bloc and are due to join on May 1, 2004.

The relationship between Warsaw and Washington had deepened even further as Poland put itself behind the US hardline stance on Iraq, sending around 200 soldiers to the Gulf to help the US-led campaign, including 50 in Iraq itself.

While political and military ties have traditionally been strong between Warsaw and Washington, bilateral economic relations have lagged behind.

Hill said the investment package would make it possible for the United States to double the amount of its investment in Poland over the next few years.

The United States is currently the second biggest investor in Poland after France, having invested 8.7 billion dollars so far.

SPACE.WIRE