Dubai's airport authorities say a purpose-build concourse for Airbus' A380 aircraft is fully open after weeks of phased-in operations.

The aircraft is a double-decker that seats 525 people and is so large some airports have to be adjusted to accommodate it.

The 20-gate concourse, which hosted its inaugural flight on Jan. 2, is part of a wider $7.8 billion expansion plan for Dubai's international airport, which seeks to become the world's busiest by 2015.

The new concourse, formally unveiled Sunday, is also a boost for the European Airbus consortium in its rivalry with Boeing Co., whose 787 has been grounded since mid-January as investigators examine possible problems in its lithium ion batteries.

The Dubai-based carrier Emirates currently flies 31 A380s and has 59 on order.