The U.S. government approved the merger of Delta Air Lines Inc. and Northwest Airlines Corp. on Wednesday, opening the way for the creation of the world's largest airline, measured by traffic.

The Department of Justice antitrust division said the merger "is likely to produce substantial and credible efficiencies that will benefit U.S. consumers and is not likely to substantially lessen competition."

A statement from the regulators said there are other competitors on "the vast majority" of routes where they today compete with each other.

Consumers will benefit from cost savings in airport operations, information technology, supply chain economics and fleet optimization, the statement said.

They may also benefit from better service.

The companies' board approved the stock-swap deal in April, a year after both airlines emerged from Chapter 11 bankruptcy protection, citing high fuel prices and the weak economy. The merged company will keep the Delta name.