Aer Lingus is set to scale back U.S.-Ireland flightsSteve Parsons/PA

Aer Lingus has announced cuts in services between the U.S. in Ireland during its upcoming winter schedule.

In a bid to cut costs during weak economic conditions and in response to a decrease in consumer demand, the Irish airline will suspend direct flights between Dublin and San Francisco, and Dublin and Washington D.C., from October 25 until March 2010.

Meanwhile, Shannon flights to Chicago will cease from September 1, while the Shannon to Boston route, which previously operated seven days a week, will be reduced to 4 days a week.

The restart of these services will be “subject to review” for next year’s summer schedule.

Aer Lingus has also stated that its Shannon to New York direct service remains “under close review.”

Its winter schedule from Dublin to New York, Chicago and Boston will remain intact.

In a statement, the company said: "Aer Lingus yields have been declining in exceptionally poor market conditions.

“Long-haul average fares fell by 19 percent in the first quarter of 2009 reflecting weak economic conditions and consumer confidence on both sides of the Atlantic."

To further cut costs and alleviate losses, Aer Lingus will cut long-haul seat capacity by 25 percent and offer pilots and cabin crew unpaid leave as it adjusts winter capacity to falling demand.

It is expected that the Irish airline’s schedule changes will anger lobby groups in Ireland’s West, who will fear a drop in American tourism and a negative effect on investments in the area by U.S. companies if direct flights between the two are drastically reduced.

Aer Lingus’ decision to cut U.S.-Shannon flights follows a 2007 controversy when the airline cut its daily flights from Shannon to London Heathrow, transferring the valuable London route to Belfast. The change resulted in job losses at Shannon airport and led to protests by trade unions and lobby groups.

The Shannon-Heathrow route has since been restored.