Delta Air Lines and Virgin Atlantic Airways has today detailed a codeshare agreement across 108 routes that offers customers seamless connections to 66 destinations across North America and the UK.

Today’s codeshare announcement coincides with Delta acquiring a 49 per cent stake in Sir Richard Branson’s airline - marking the next step towards a full joint venture between the two carriers.

Virgin Atlantic will place its code on 91 Delta routes, including both trans-Atlantic and domestic US routes.

Delta will place its code on 17 Virgin Atlantic routes, including the recently launched Little Red domestic U.K. services connecting London to Manchester, Edinburgh and Aberdeen.

“This is a strategic investment that enhances Delta’s network with greatly improved access to London Heathrow, the leading marketplace on the trans-Atlantic,” said Ed Bastian, Delta president.

“As we unite two leading global airline brands in an innovative partnership that focuses on delivering enhanced benefits and services for our customers, we also become a more formidable competitor across the Atlantic.”

The two airlines announced their intention to enter into a joint venture agreement in December 2012.

Last week unconditional merger clearance was granted by the European Commission and the US Department of Justice closed their review of the transaction.

As of today, Delta has successfully completed its acquisition of a 49 per cent stake in Virgin Atlantic.

The US Department of Transportation is currently reviewing the parties’ application for antitrust immunity relating to the proposed joint venture of the parties’ operations on non-stop routes between the US and the UK.

This review is expected to be completed during third quarter of 2013, and the implementation of the Delta/Virgin Atlantic joint venture is anticipated to occur in the first quarter of 2014.

Once implemented, this will deliver further significant additional consumer benefits and vibrant competition to the trans-Atlantic market.

Craig Kreeger, Virgin Atlantic chief executive said: “Today is an important day for Virgin Atlantic and our customers in both the US and UK.

“As new shareholders in the airline, Delta is an important ally in the all-important trans-Atlantic market. We can stand firm together against the competition and can now offer more destinations, a smoother connecting airport experience and ultimately the best trans-Atlantic on board experience.

“Virgin Atlantic’s award-winning customer experience is loved around the world and we look forward to sharing our unique Clubhouse and in-flight hospitality with many Delta passengers over the years.”