Transatlantic business partners British Airways, American Airlines and Iberia carriers are expanding the number of codeshare routes between North America and Europe.

The first sales date of the expanded codeshare co-operation is today (December 20), with most travel starting on December 28. In total, it adds up to 317 new codeshare routes.

The partners claim the codeshares will offer passengers in the US, UK, Spain, Mexico and other European countries better connections to flights across the Atlantic.

American is adding its (AA) code to an additional 57 BA flights to 16 destinations and four Iberia flights to two destinations. BA will add its (BA) code to 42 additional American Airlines flights to 18 markets and 56 Iberia flights to eight markets.

Iberia will add its (IB*) code to 72 American flights in 23 markets and 86 BA flights to 24 markets.  As a result of the joint business, BA code will be published on more than 2,800 American and Iberia flights serving more than 336 destinations.

American Airlines code will be displayed on over 800 BA and Iberia flights to 174 destinations. Iberia will publish its code on more than 350 BA and American flights to 80 destinations.

In total, the joint business will serve more than 400 destinations in over 100 countries with approximately 5,200 daily departures. Members of the three airlines’ frequent flyer programmes will be able to earn points or miles on the new codeshare flights.

BA commercial director Andrew Crawley said: “When we launched the joint business in October, we said that we would be rolling out more benefits to customers and this introduction of more codeshare flights across our three airlines is exactly that.”

American’s chief commercial officer Virasb Vahidi said: “Expanded codesharing makes it easier and more convenient for our respective customers to travel on the global networks of all three airlines and delivers on our promise of more choices, easier connections and a better overall travel experience.”

The three airlines previously announced five new routes from spring 2011: New York JFK-Budapest and Chicago-Helsinki (operated by American), Heathrow-San Diego (operated by BA) and Barcelona-Miami and Madrid-Los Angeles (operated by Iberia).

American will also add frequencies from New York to Barcelona and Miami to Madrid.