Irish airports are set to become the first outside the Americas to offer full U.S. immigration checks before departure, potentially boosting their position as transatlantic hubs, the Irish government said on Nov. 14.

Dublin and the busy stopover point of Shannon in the west of Ireland already offer immigration clearance but passengers must still clear customs and agriculture inspection on arrival in the United States.

Ireland's transport minister Noel Dempsey said he would sign an agreement with U.S. Secretary of Homeland Security Michael Chertoff early next week which will allow Shannon to offer full clearance facilities by next summer and Dublin in 2010.

"Flights from Shannon and Dublin airports will be treated like domestic flights in the U.S.," Dempsey said.

"Airlines will be able to fly into less congested and less expensive domestic terminals at U.S. airports, while passengers will be able to check their baggage through to their final destination," he said in a statement.

At present only airports in Canada and the Caribbean offer full U.S. immigration services, Shannon Airport Authority said.

Dempsey said British Airways had said it was considering a business class only service from London City Airport to the United States with a stopover at Shannon to take advantage of the pre-clearance services.

In a blow to the airport this year, former state airline Aer Lingus stopped flying from Shannon to London Heathrow and started services from Belfast instead due to cost issues.

Europe's biggest low-cost airline Ryanair said this month it was planning to cut flights from Shannon by up to 75 percent from November as they will not be viable after the introduction of a new Irish airport departure tax.