AIG, the insurance giant, and investment firm Global Infrastructure Partners are circling Prague airport, which is due to be auctioned for around €3bn (£2.4bn) at the end of the year.
The duo want to top up their aviation assets, which currently include London City airport. They are also in the running for Southend airport, which has shortlisted seven bidders.
An aviation source confirmed: "London City shareholders are looking at a bid for Prague."
Another probable bidder is ADG, the French airports group which announced earlier this year that it was interested in teaming up with Ontario Teachers, the Canadian pension fund. Spain's Abertis Infraestructuras is also known to be eyeing up the airport.
Credit Suisse is advising the Czech government on the privatisation.