The application was denied by Justice Ruth Bader Ginsburg, the court’s public information office said.
The combination of American’s parent, AMR Corp, and US Airways Group would create the world’s largest carrier and follow last month’s resolution of antitrust objections by the U.S. Department of Justice.
In their appeal to the Supreme Court, plaintiffs led by California resident Carolyn Fjord warned that “irreparable injury” could be caused to the domestic airline industry if the deal goes ahead as planned. They fear the merger will drive air travel prices up and service down and make planes more crowded.
The merger is expected to be consummated before the opening of U.S. securities markets on Monday.
A federal judge on Friday rejected the previous attempt by the group to stop the merger.
If one high court justice denies a stay request, the same application can be made to another justice but such moves are rarely successful. Usually, if a request is made to a second justice it will be referred to the full court.
The case is Fjord v. AMR Corp et al, U.S. Supreme Court, No. 11-15463-SHL. The main bankruptcy case is in U.S. Bankruptcy Court, Southern District of New York, re: AMR Corp et al, 11-15463.