A federal appeals court has denied MGM Resorts International’s bid for a rehearing in its attempt to overturn the 2015 state law that enabled the Mashantucket Pequot and Mohegan tribes to solicit casino site proposals.

In an order filed late last week in Manhattan, the 2nd U.S. Circuit Court of Appeals denied a petition MGM Resorts  filed in July and amended last month. MGM Resorts sought a rehearing in its appeal of a lower court’s dismissal of MGM's claim that the 2015 law is unconstitutional. A three-judge panel of the appeals court unanimously upheld the dismissal in a June decision.

MGM also has vowed to take legal action over the 2017 law authorizing the tribes to proceed with development of Connecticut’s third casino — a commercial enterprise on non-tribal land — in East Windsor.

Asked for comment Monday, an MGM Resorts spokesman referred a reporter to a company executive's previous statement.

"As we have been saying all along, we believe this new law violates both the state and United States constitutions, and we will continue to argue our case vigorously in court,” Uri Clinton, MGM senior vice president and legal counsel, said last month. 

The state Office of the Attorney General declined to comment on the appeals court’s denial of MGM’s petition.

MGM sought a rehearing before the three-judge panel or, alternatively, before a larger number of 2nd Circuit Court judges.

“The panel that determined the appeal has considered the request for panel rehearing, and the active members of the Court have considered the request for rehearing en banc,” the court’s order reads. “It is hereby ordered that the petition and amended petition are denied.”

The tribes are awaiting U.S. Bureau of Indian Affairs approval before proceeding with their East Windsor project.

MGM Resorts is building a resort casino in Springfield, Mass., less than 15 miles north of East Windsor. The Springfield casino is scheduled to open next September.

b.hallenbeck@theday.com