Passengers have more choice of transatlantic flights than ever before from this week as decades of regulation between Europe and the US end in the first stage of an open-skies agreement.

More than 7,000 additional seats should be available from London as five carriers launch services to the US from Heathrow. Until now, US flights from Heathrow have been restricted to British Airways, Virgin Atlantic, American Airlines and United Airlines.

Continental Airlines will launch twice-daily services to its hubs at New York Newark and Houston, and Delta Air Lines will begin Heathrow services to New York JFK twice a day and to Atlanta daily.

US Airways will offer daily flights from Heathrow to Philadelphia and, in the first move of its kind by a European carrier, Air France will launch daily services from Heathrow to Los Angeles on Monday.

Northwest Airlines will offer a Heathrow-Seattle service from June 1. In the meantime, Northwest will launch services from Amsterdam to Portland and Dallas/Fort Worth and from Paris to Minneapolis-St Paul.

United Airlines weighed in last week, announcing the launch of a daily Heathrow-Denver service from Monday. British Airways will fight back by promoting the ease of travelling through Heathrow’s Terminal 5, which opened on Thursday and which BA has to itself.

However, Virgin got its retaliation in first by opening an upper class facility at Terminal 3 in November that offers passage through check-in and security in six minutes.

BA will take advantage of transatlantic liberalisation beyond Heathrow by launching services from Paris to New York in June aboard a new subsidiary, OpenSkies.

However, OpenSkies remains the subject of a challenge by pilots, who have voted to strike – pending legal clarification in the High Court.

BMI, which lobbied hardest for open skies, will not launch any new services for now.