New routes from Heathrow Airport in the event of the hub's expansion could boost Northern Ireland businesses and make the region a more attractive location to global investors, it's been claimed.
Matt Gorman, Heathrow's director of sustainability, was speaking at a Northern Ireland Chamber of Commerce event which also heard an estimate by Oxford Economics that flights between Belfast and Heathrow support 900 jobs here.
According to the chamber, George Best Belfast City Airport's top five onward destinations to existing routes via Heathrow are Hong Kong, Kuala Lumpur, Geneva, Toronto and Singapore.
But Mr Gorman said expansion at Heathrow would add 40 new routes to international markets and rapidly growing emerging economies in Asia, Latin America and North America.
Heathrow recently submitted refined plans for a third runway to the Airports Commission.
Mr Gorman said that Heathrow said that the airport had set up a regional connectivity task force to develop policy proposals and recommendations for improving regional access to an expanded Heathrow.
"Northern Ireland business is heavily reliant on connections to international markets through Heathrow," he said.
"We want to add up to 40 new long-haul, direct routes and improve our connectivity to other UK airports such as George Best Belfast City Airport."
Ann McGregor, chief executive of Northern Ireland Chamber of Commerce, added: "An expanded Heathrow would further improve the attractiveness of Northern Ireland to global investors."
As an example, the chamber cited law firm Pinsent Masons, whose Belfast staff and clients rely on the daily link to Heathrow to connect with their global network of 20 offices across Europe and Asia. As the firm's network grows, new routes, which are currently unavailable due to constrained hub capacity at Heathrow, will be required, the chamber said.
The onward connections from Heathrow could be vitally important for USA-bound travellers who may be left inconvenienced following United Airline's recent decision to halt the route between Belfast International Airport and Newark between January 6 and March 11 next year.