(CNN) -- The U.S. Supreme Court has cleared the way for American Airlines and US Airways to merge into world's largest airline company.
Late Saturday night, Justice Ruth Bader Ginsburg declined to hear a stay request filed by a consumer group opposing the merger.
Earlier in the day, a federal appeals court in New York also denied an emergency stay -- which prompted the consumer group to turn to the Supreme Court to block the deal.
The passenger group believes that a merger will result in higher fares and reduced choices for fliers.
With the Supreme Court removing the last roadblock, the two airlines can sign papers before the financial markets open Monday.
For the foreseeable future, though, passengers will still be booking flights under both the American Airlines and US Airways names.
Details about when the airlines will combine reservations and ticketing, frequent flier clubs and other operations are still being worked out, and those combinations are not likely until the beginning of 2014, at the earliest.
But the combined company will be the largest airline in the world in terms of revenue, passengers carried and the number of miles flown by paying passengers, surpassing United Continental Holdings, which was also formed by a merger.
CNN's Supreme Court producer Bill Mears contributed to this report.