A THIRD runway at Heathrow would give Scotland access to the world's largest hub airport "on its doorstep" and double the UK's exports, business leaders have been told.

Heathrow chief executive John Holland-Kaye said the UK's only hub airport should be expanded over a rival bid from London Gatwick because it was the only option which would connect the UK, and Scotland, to the world and keep it competitive in the global marketplace.

Speaking yesterday at a conference of aviation representatives in Glasgow organised by the Scottish Council for Development and Industry (SCDI), Mr Holland-Kaye said adding a third runway could double UK exports by 2020 and boost the number of long-haul destinations served by Heathrow from 80 to 120.

He said: "It would be the best connected airport in the world, and Scotland would have that right on its doorstep. We would have more capacity than Paris, Amsterdam or Frankfurt."

Mr Holland-Kaye and his counterpart at Gatwick, Stewart Wingate, were making their cases to Scottish business leaders a day after the Airports Commission opened its public consultation on the airports' rival bids for expansion.

Heathrow bosses want to build a third runway while those at Gatwick want to add a second to meet growing demand for domestic and international routes, especially in rapidly growing economies such as China.

The UK Government-appointed Commission -which is also considering a third option not favoured by Heathrow bosses to extend the airport's north runway - will recommend one of the proposals next summer.

Mr Holland-Kaye said Heathrow was the conduit for more than one-quarter of the UK's exports, including £80 million of Scottish salmon, annually, compared to less than the two per cent which passes through Gatwick.

Mr Wingate told the conference a second runway at Gatwick would keep fares lower for Scottish passengers and better serve the growing low-cost market.

He stated Gatwick already served a number of far-flung destinations such as Moscow, New York, Hanoi, Ho Chi Minh City and Jakarta but a second runway would "accelerate that growth" while offering passengers comparatively cheaper flights than Heathrow.