Poor ticket sales have triggered the closure of key international air links this winter. Birmingham’s only American connection is to be grounded, while British Airways will stop flying from Heathrow to western Norway’s two biggest cities.

United Airlines says its last-ever flight on the Birmingham-New York (Newark) route will take of on 5 October 2017. A spokesperson said: “We have regretfully taken this decision because of the route’s poor financial performance.”

Passengers with existing bookings are being contacted and offered alternative flights or refunds.

A number of airlines have flown between Birmingham and New York over the years, with British Airways operating to JFK in the 1990s. The United link has operated for 20 years.

In January, American Airlines abandoned its Birmingham-New York JFK service after 20 months.

The airport issued a statement saying it was “disappointed” by United’s decision. While the Boeing 757-operated route represents less than 1 per cent of Birmingham’s passenger numbers, it is an invaluable link in terms of profile.

“We expect to be making an announcement shortly regarding another airline serving North America non-stop from Birmingham, giving passengers additional choice,” the statement continued. There has been speculation that either Norwegian or Thomas Cook Airlines could launch transatlantic routes from the West Midlands airport.

United is also grounding its Glasgow-Newark service for six months over the winter, “in response to a seasonal reduction in market demand”. The airline’s Edinburgh-Newark link will continue.

Norwegian’s new routes from Edinburgh to Stewart in upstate New York, Hartford in Connecticut and Providence in Rhode Island will continue through the winter, eroding demand for United’s long-established services from Scotland’s two biggest cities to Newark.

In addition, Dublin airport has become a key hub between UK regional airports and the US, with passengers able to clear immigration and customs in the Irish capital.

Closer to home, British Airways is dropping services from Heathrow to both Bergen and Stavanger on 28 October 2017, “as both routes are no longer commercially viable”. BA has a single daily round-trip to each city.

Norwegian is the main competitor, with double-daily services from Gatwick to both airports.