Final bids of up to £1 billion for the takeover of Stansted are expected to be tabled this week.
The Essex airport was put up for sale by the former BAA following a lengthy battle with the Competition Commission.
Final bids are due to be made by Wednesday with a preferred bidder likely to be appointed by the end of the week, the Sunday Times reported sources as suggesting.
A joint venture between Manchester Airports Group and Australian infrastructure investor Industry Funds Management is the favourite to win the bidding battle.
It faces competition from Malaysian Airports and Australian investment bank Macquarie.
A consortium led by New Zealand infrastructure firm Morrison & Co withdrew last week after failing to secure funding, the newspaper said.