Aer Lingus may reopen flights to the west coast of American but only if multi-national employers stump up some of its costs, Newstalk has learned.

The airline has written to several companies in the last few weeks to say it would consider flying to San Francisco four times a week.

There have been repeated calls for the service because of the importance of foreign direct investment to Ireland, particularly from companies based on the west coast where the likes of Google and Facebook are based.

Aer Lingus told the companies the service to San Francisco could reactivated if the companies supported the plan for three years. It pulled out of the route a few years ago when it scaled back its transatlantic services because of poor demand for seats.

Aer Lingus wants the companies to provide an indication of how much travel they would be prepared to spend on the flight for the three year period.

The companies would commit to spend a certain percentage of their travel with Aer Lingus or its code share partner United Airlines.

If Aer Lingus were to incur losses on the route then the companies would effectively subsidise it by paying the difference between what they said they were prepared to spend and their actual spending.

It’s not known yet how far along the proposal is or if any company has signed up yet.

Aer Lingus said in its proposal that San Francisco offers connections to other key cities on the west coast including Seattle and Portland.

It also said the flight would be pre-cleared for customs and immigration at Dublin Airport.