Singapore Airlines (SIA), the island state's national carrier, signed an agreement with the European giant aircraft manufacturer Airbus to buy nine more A380s on December 20.

The agreement confirmed the order announced by SIA in July this year, which brought the amount of A380 ordered by SIA to 19.

Deliveries for the additional nine A380s, will commence in January 2010 and complete in early 2011, SIA said in a statement.

The agreement also includes an option for six more of the superjumbos and SIA also signed a deal to lease 19 A330-300 wide body jets from Airbus.

SIA became A380's first customer when it ordered 10 such planes, worth 8.6 billion U.S. dollars, in 2000.

The A380 roll-out has been delayed three times due to "wiring problems", and the first A380 is expected to be delivered to SIA in October 2007.

The statement also said that SIA has reached settlement with Airbus on issues relating to delays of deliveries of the A380, but the terms of the purchases and settlement were confidential.

The superjumbo, the world's largest commercial aircraft, is designed to transport between 555 and 840 passengers over distances of up to 15,000 km.