With Aer Lingus refusing to consider a reversal of its decision, transport minister Noel Dempsey ruling out government intervention and other airlines unlikely to use valuable Heathrow slots for a Shannon service, attention is now turning to Amsterdam's Schiphol and Paris's Charles de Gaulle airports as a means of providing the global connectivity that multinational companies in the area insist they need.

Sources say the Shannon Airport Authority has been working for some time on the possibility of inviting an airline to service another of Europe's four main hub airports.

Schiphol offers the same level of connectivity to global destinations as Heathrow does and is regarded as considerably easier to travel through.

Dutch airline KLM would be the most obvious provider of such a service . . . and, unlike the Aer Lingus service to Heathrow, would offer sameairline transfer to the hundreds of destinations it services from Amsterdam.

"All these options are being explored, " one well-placed source said.

Meanwhile, a spokesman for Air France-owned CityJet confirmed it would examine the business case for a service between Shannon and Charles de Gaulle, from which Air France flies to 400 worldwide destinations. The spokesman said the airline would first need to examine what level of connectivity existed on the ShannonHeathrow route.

"Cityjet will look at it but it has to do the figures, " he said, adding that it would also consider operating a service to London City airport.

Shannon is well served by direct routes to North America and mainland Europe, but the loss of the Heathrow service leaves business lacking vital connectivity for destinations in Asia, Australia and Africa. However, a new route to either of the two hub airports of Paris and Amsterdam would counter this.

"It would certainly call a lot of the bluff that this issue is all about connectivity, " said one close observer.

However, sources in government and aviation circles conceded that any airline would be able to "drive a really hard bargain" because of the withdrawal of Aer Lingus from the Heathrow route.