The head of Melbourne Airport has defended car parking prices at Tullamarine, saying its fees are competitive.

An Australian Competition and Consumer Commission (ACCC) report released earlier this year found Melbourne Airport made the most profit from parking of any Australian airport.

"We're two-and-a-half times the size of Sydney, so of course we make more money," said Lyell Strambi, CEO of Australia Pacific Airports Corporation (APAC) which owns Melbourne Airport.

"If you look at the prices of car parking ... of the big airports in Australia, we're one of the cheapest and most competitive."

Mr Strambi told ABC Radio Melbourne's Rafael Epstein that around 20 per cent of the airport's revenue came from parking.

"I think we're probably the biggest car park in the Southern Hemisphere — we have 26,000 spaces."

Parking cheaper than CBD

Mr Strambi said one in five people coming to the airport used its parking facilities.

"There is a lot of competition from other modes of transport [and] other parking operators, and I think when you do the price check comparisons we don't stack up too badly," he said.

He said the airport's parking fees compared favourably with prices in Melbourne's CBD.

"When I park in the city, and I do often for meetings, I'll pay $60 plus for half a day and yet I can park at the most convenient park at the airport for $59 a day.

"If you book online and stay 10 days you can get that ... for $70."

Profits 'help pension funds'

Mr Strambi said Melbourne Airport, which handles 35 million passengers a year, was a business and as such it was obliged to turn a profit.

"Like all businesses we have our shareholders, those shareholders tend to be the big institutions like the AMPs of the world," he said.

"People like me and you, who have our pension funds, want to see decent returns from those businesses."

Listeners messaging ABC Radio Melbourne were unimpressed by Mr Strambi's arguments, with one saying: