An alternative to the deal collapsing could be an agreement between the shareholders in which they accept selling smaller stakes in return for a lower sum.
However, a source close to the talks said this could leave some investors dissatisfied.
Another option could be for shareholders to abandon tag-along rights altogether, meaning Spain’s Ferrovial can offload its shares having spent 17 years as Heathrow’s largest investor.
The issue of Heathrow’s ownership has been hanging over the airport for months, at a time when new chief executive Thomas Woldbye is attempting to overhaul the business.
Since the rebound in travel post-pandemic, the issue of capacity has been thrust back onto the agenda at Heathrow – raising renewed questions over the airport’s plans for a third runway.
Restrictions relating to its expansion have led to high-profile industry chiefs arguing that Heathrow has lost its status as a global transport hub.
Paul Griffiths, former managing director of Gatwick Airports and current boss of Dubai Airports, said Heathrow has suffered from its “shortage in capacity”.
Current shareholders in Heathrow have also previously been criticised for starving the company of investment, with scrutiny placed on £4bn of dividends extracted before the pandemic. Since then, debts in the business have ballooned to almost £20bn.
Heathrow and Ardian declined to comment.
Robert Johnson is a UK-based business writer specializing in finance and entrepreneurship. With an eye for market trends and a keen interest in the corporate world, he offers readers valuable insights into business developments.