Virgin Atlantic Airways Ltd., which flew solo for a decade as rivals formed the global groups that dominate the industry, may be about to come in from the cold as Singapore Airlines Ltd. considers selling its 49 percent stake.

With Delta Air Lines Inc. mulling a bid, according to two people familiar with the matter, Virgin could form a North Atlantic venture with the U.S. carrier and its European partner Air France-KLM Group while joining the pair’s SkyTeam alliance.