The world's biggest airliner, the European Airbus A380, touched down in Singapore on Friday, completing its first flight to Asia - the most competitive market for planemaker Airbus and its U.S. rival Boeing.

The double-decker superjumbo, designed to carry 555 passengers but with room for more than 800, landed at the city-state's Changi airport after a 12-hour flight from Airbus' headquarters near Toulouse in southern France.

The A380, as long as eight London buses and with enough room on its wings to park 70 cars, heralds a new era in passenger travel and is a challenge to Boeing in the battle for market share in the global aviation industry.

Airbus, part of aerospace group EADS, has received 159 orders and commitments from 16 customers for the four-engined plane, still short of the 250 it says is the break-even point.

The planemaker has three A380s in flight testing and expects to attain certification in the last quarter of 2006, in time for first delivery to initial operator Singapore Airlines.

The A380 has cost 12 billion euros (8 billion pounds) to develop and is running up to six months behind schedule.

The plane's Asian tour was delayed by four days because engine supplier Rolls-Royce had to replace two of its four engines before the trip after one of them overheated during a test flight two weeks ago.

A subsequent tour to Australia remains unchanged and the plane will then fly on to Kuala Lumpur as Airbus carries out airport compatibility checks with the mammoth double-decker.