A combination of higher landing revenues, retail growth and passenger traffic boosted Sydney Airport's first half underlying profit by 12.5 per cent.

The unlisted Southern Cross Airports Corporation, the airport's holding company, reported earnings before interest, tax, depreciation and amortisation (EBITDA) of AU$293 million, with revenue improving 8.8 per cent to AU$358 million on January 25.

Aeronautical revenue (mainly landing fees) grew 8.8 per cent to AU$146.3 million, while retail growth contributed AU$83.2 million, up 6.4 per cent.

During the period, Jetstar International began three services a week to Phuket, Ho Chi Minh City and Honolulu, as well as two services a week to Bali.

Jetstar and Virgin Blue also enjoyed strong local growth, prompting an increase in passenger traffic at Sydney Airport's domestic terminal, T2.

Sydney Airports Corporation chief executive Russell Balding said the company had benefited from improvements at the airport, including a retail makeover of the T2 facility.

"We were pleased by the upturn in international traffic in the second quarter and continue to work hard on our airline marketing initiatives," he said.

The listed Macquarie Bank offshoot Macquarie Airports has a 55.8 per cent economic interest in Sydney Airport. (Australian dollar is the currency used in this report unless otherwise stated)