MADRID - SPAIN'S prime minister unveiled a major commuter train and subway hub in the heart of Madrid on Saturday.

The six-year project at Sol square cost euro570 million (S$1.2 billion) and caused considerable disruption after archaeological remains from a long-forgotten 15th century church were unearthed, causing a 10-month delay.

The station, which adds two commuter lines to the three subway lines already in service, is now expected to handle about 70,000 passengers daily. It will be fully operational Sunday and eventually link central Madrid with the main international airport.

Prime Minister Jose Luis Rodriguez Zapatero said the project will help Madrid's bid to host the 2016 Olympics.

The ruins of the Buen Suceso church have been housed in a museum within the station, which boasts a 7,500 square metre entrance hall.

A new rail tunnel will allow passengers to reach the mainline stations of Chamartin and Atocha - the hub of Spain's AVE bullet train network - directly from the Spanish capital's most emblematic central square.

Sol is known as 'kilometer zero,' the point from which geographical distances were measured when Spain governed a vast global empire.

The connection between Barajas airport will begin operating in 2010 and is due to reduce travel time from Sol to 20 minutes from around an hour. -- AP