The $3.2 billion merger, which is pending a shareholder vote next month, is expected to close on October 1, 2010, the companies said in a press release. The airlines announced the all-stock deal in May.
The antitrust probe was closed after the airlines agreed to transfer takeoff and landing rights and other assets at Newark Liberty Airport to Southwest Airlines (LUV, Fortune 500), the Justice Department said in a statement.
"The completion of DOJ's review is an important step on our journey of creating the world's leading airline," said Jeff Smisek, Continental's chief executive. "The DOJ's decision permits us to clear one of the last regulatory hurdles to closing our merger."
The combined company, which will fly under the United (UAUA, Fortune 500) moniker and Continental (CAL, Fortune 500) logo, would be larger than Delta Air Lines (DAL, Fortune 500), which became the country's largest airline when it merged with Northwest Airlines in 2008. It is expected to serve more than 144 million passengers per year and fly to 370 destinations in 59 countries.
The European Commission on the airlines approved the proposed merger in July.