( CNN ) -- One of the most valuable routes in the airline industry is the one that joins New York to London . It is the world 's busiest route , one particularly frequented by business travelers , and currently , it is dominated by United Airlines . All that is set to change , thanks to a pivotal partnership between Delta Airlines and Virgin Atlantic . Last month , the two airlines unveiled a codeshare agreement across 108 routes , with Delta acquiring a 49 % share of the British carrier . For Delta , the deal provides access to a market that , though lucrative , has been difficult for them to crack . `` Heathrow is the most important destination for the U.S. business traveler , and we 've not been able to provide the global frequency that our customers need , '' admits Edward Bastian , Delta 's president . `` Virgin was the best way to get to them . '' Unlike Virgin Atlantic , which has experienced two years of steady financial losses , Delta has been in an upward expansion . It is the fastest-growing carrier in New York -- abetted by a massive expansion of two of the city 's major hubs , including a $ 1.4 billion renovation of Terminal 4 at JFK , and $ 100 million upgrade of its facilities at LaGuardia Airport . While Delta is gaining momentum in North America , procuring slots at Heathrow has proved arduous for the airline , according to George Ferguson , senior airline and aerospace analyst at Bloomberg Industries . Read more : Luxury jets for the long haul . `` The largest number of slots at Heathrow are dedicated to Virgin and British Airways flights . Delta has had a hard time getting in there , '' he admits . `` This deal really gives them a lot of access to Heathrow , which is an important market in New York . '' Currently , Delta has nine flights operating between Heathrow and the U.S . When the partnership takes effect , that number will jump to 23 . Compared to Delta , Virgin is a much more niche airline . It serves a smaller , predominately British clientele , providing them with a more upmarket experience . Despite Virgin 's strong brand , its image does n't resonate as well outside the United Kingdom . Ideally , the deal with Delta will introduce the carrier to a wider audience . `` I think the spirit of our company will be very attractive to the U.S.-based customers that Delta currently serves , '' says Craig Kreeger , CEO of Virgin Atlantic Airways . `` I think that by becoming more successful and being able to generate more fans in the United State , it 's going to spur even more innovation ( at Virgin ) . '' As the two companies join houses , so to speak , experts are pondering which brand will be more prominent . `` From a Virgin perspective , I expect not much will change , at least not for a while '' says Ferguson . `` Virgin has a pretty strong brand across the Atlantic -- the better brand right now -- and Delta 's going to want to leave that in place . '' Discover which airport is the worst for delays . Asked if there 's a chance Virgin might lose its identity in the process , Kreeger says he 's not worried . `` The Virgin brand and Virgin style is one of the things that attracted Delta to us in the first place , '' he says . `` I think they 're looking forward to being able to offer their customers more choice . '' For the deluge of passengers that fly Delta and Virgin across the pond , the partnership could ideally result in cheaper fares . `` I see them being able to give corporate customers much more options , and I see them really being able to kick off some extensive routes with above-average yields , '' says Ferguson , who adds that in the airline industry , fuller planes usually results in cheaper tickets . `` London and New York are sort of dominated by the financial services business , which has taken it on the chin lately , '' notes Ferguson . `` As a result , you have a consumer that is more price conscious and you need to find a way to get them a cheaper ticket while still making money . That 's why you need to get planes full . For Virgin , this is the start of that process . ''
trans-Atlantic takes 49 % stake in Delta . Airlines hope that codeshare will increase their Delta success . UK - UK routes are the most world 's busiest and lucrative . Virgin seen as a much more niche airline than Delta .