UPDATE 1-Delta in talks for Virgin Atlantic stake-sources

NEW YORK/LONDON, Dec 2 (Reuters) - Delta Air Lines Inc has held talks to buy a 49 percent stake in British carrier Virgin Atlantic that is currently held by Singapore Airlines, two people familiar with the matter said on Sunday.

Delta, the second-largest U.S. airline after United Continental Holdings, has been looking to acquire a stake in Virgin Atlantic for more than two years in an effort to expand its access to London's Heathrow airport, the people said.

Previous deal talks broke down over price and other issues, and there is no guarantee that the recent discussions would result in a pact, the people said. News of Delta's interest in Virgin was first reported by the Sunday Times of London.

Delta has made clear that it would like to expand at Heathrow, a lucrative airport for prized corporate passengers where landing slots are generally hard to acquire.

Delta's SkyTeam global alliance, which includes Air France and 18 other airlines, trails its oneworld and Star Alliance counterparts in slot access at Heathrow.

Richard Branson, who set up Virgin Atlantic in 1984, has been weighing the airline's future for years and two years ago appointed Deutsche Bank to examine offers.

"We are always talking to many airlines on a number of different matters but we never comment on the details of these discussions," a Virgin Atlantic spokeswoman said on Sunday, after the talks were reported by the Sunday Times newspaper.

Delta declined to comment. Singapore Airlines was not immediately available for comment outside regular business hours.

Capacity-constrained Heathrow, Europe's busiest airport, is operating at close to full capacity after Britain's coalition government blocked its expansion in 2010.