Delta Air Lines agreed to buy a 49 percent stake in Virgin Atlantic, creating a joint venture that would expand Delta's access to London's Heathrow Airport and increase competition in the lucrative transatlantic market, according to Reuters.

The partnership would let both carriers offer more flights at Heathrow, Europe's busiest airport, where landing-slot constraints have limited their growth. It also gives Delta the ability to attract prized corporate travelers as it competes with industry leader United Continental and American Airlines, whose partnership with British Airways dominates travel between the United States and London.

Delta and Virgin said their agreement would generate new revenue and leverage Virgin's strong luxury brand. The venture also will be "very positive and accretive for our long-term partners ... KLM, Air France and Alitalia," Delta Chief Executive Richard Anderson said, referring to the European airlines with which Delta already has partnerships.