$7b third airport proposed for Melbourne

An investment fund will next week present its plans to the Victorian government for a $7 billion third Melbourne airport.

An investment fund will present the Victorian Government with a plan for a third Melbourne airport. (AAP)

An investment company wants to build a $7 billion third airport in Melbourne without using taxpayers' money, but Victoria's premier is focusing on the two airports the city already has.

Paragon Premier Investment Fund says it has a letter of intent from an unnamed financier to build an airport about 75km southeast of the CBD, near Koo Wee Rup and Lang Lang.

Managing director Alande Mustafa Safi said the plan for the airport, which would be subject to state and federal approvals, would be presented to the government the following week.

"We're not asking for any government backing or funding," Mr Safi told AAP on Tuesday.

"We don't need a penny to build this."

But Premier Daniel Andrews said the government was focusing on the two airports Melbourne already has - Tullamarine and Avalon.

"I haven't seen any proposals other than the stuff that's been in the media today," Mr Andrews told reporters.

"It is fair to say we are focused on upgrading connections to Melbourne airport (Tullamarine).

"We're also focused ... on Avalon.

"There's every chance there could be tens of thousands of people working down there."

Mr Safi said Paragon's proposed airport would be fully operational by 2022 and at least as big as Tullamarine.

It would focus initially on cargo and domestic flights before extending to international tourists.

Fellow fund director Gerard Kennedy said Mr Safi wasn't looking to invest in an airport until he was approached in Dubai.

"He got tapped on the shoulder from some people who said 'we want an airport in southeast Victoria. We want it for this reason. We want to see these huge advantages of that particular area. We want people to be able to fly directly there'," Mr Kennedy told ABC radio.

Shadow attorney-general John Pesutto said that the coalition was "very keen to look at ideas like this in much greater detail".

In 2013, the then-coalition government called for a new airport in Melbourne's southeast to cope with population growth.

Infrastructure Victoria declined to comment on the latest proposal, but its 30-year strategy released in December said a third airport "could potentially offer benefits for both passengers and freight".

Mr Safi previously raised plans for a $2 billion airport in Melbourne's southeast in March.