George Best Belfast City Airport is about to be sold as part of a deal worth nearly £500million the Belfast Telegraph can reveal.
The international fund which owns the airport is on the verge of selling up to another consortium.
A spokesman for the airport said it would not be commenting on the deal.
Current owners Eiser Global Infrastructure Fund, based in London, bought the airport for £132.5m in 2008.
They are thought to have spent around £20m on improvements over the last eight years.
Now a consortium led by 3i Infrastructure is expected to make a final binding offer over the next few weeks.
According to news service InfraNews, the consortium is expected to pay around €600m (£480,769,000) for the fund, which also includes UK gas business ESP Utilities, Spanish road company Autovias de Peaje en Sombar and Spanish solar firm ASTE.
3i had made a non-binding offer for the fund late last year but refused to comment on the latest developments in the process.
"I'm afraid we don't comment on speculation regarding our future intentions," it said. Eiser also refused to comment on the deal.
It took control of ABN AMRO, which bought the airport from former Spanish owners Ferrovial Group. Ferrovial had paid £35m for the airport in 2003.
More than 2.6 million people used Belfast City Airport last year - an increase of 5.4% on 2014, according to figures from the Civil Aviation Authority (CAA).
In 2015, numbers using rival Belfast International Airport were up 8.9% to almost 4.4 million. Belfast City has links to sun destinations like Faro, Palma, Malaga and Alicante.
UK regional airline Flybe is its biggest airline tenant, while British Airways, Aer Lingus and Dutch airline KLM also fly from it. BA sister airline Vueling withdrew last year after running a Barcelona route for less than a year.
Belgian airline Brussels Airlines last month launched a flight to Brussels from the airport.
There are also two direct Heathrow flights operated by Aer Lingus and British Airways and a London City Airport link by Flybe.
The consortium which is expected to bid for the airport and other assets is made up of 3i, which is listed on the London Stock Exchange, and other institutional investors.
Speaking earlier this year, Belfast City Airport chief executive Brian Ambrose said he hoped the airport would reach 4 million passengers annually within the next decade. He said he was not bruised by the decision of Ryanair to set up in Belfast International Airport, six years after withdrawing from Belfast City after a dispute over a runway extension.
"We believe that even with that new competition we will continue to grow," Mr Ambrose said.