Sydney: A consortium led by Macquarie Bank has won the battle for Sydney Airport with a bid of Australian Dollar 5.6 billion ($ 3.2 billion) in the world's largest airport trade sale, the government said on June 25.

The Southern Cross group beat the AMP-led Gateway consortium and the International Connect group in a tough and protracted contest for the 99-year lease of Australia's major international airport and gateway to its tourist industry.

The price, which was greater than expected and more than the combined proceeds of 17 other privatised Australian airports totalling Australian Dollar 4.1 billion, will go to repaying debt, the government said.

"This Australian Dollar 5.6 billion sale represents the biggest government trade sale in Australian history and it's in fact the world's largest ever airport trade sale," Finance Minister Nick Minchin told reporters.

"We believe the sale price does reflect the value of the airport," he added.

Minchin said the bidding process was very competitive but the Southern Cross bid had been assessed as best in meeting the government's objectives. These included management capabilities and a commitment to develop airport services.

The Southern Cross group, which also includes the German airport operator HOCHTIEF Airport GmbH and the Commonwealth Bank of Australia, has given commitments to a substantial investment programme, including expanding runways and new retail services.