A federal appeals court has upheld former Mashantucket Pequot Chairman Michael Thomas’ conviction and 18-month prison sentence on charges he embezzled more than $100,000 from the tribe that owns Foxwoods Resort Casino.

In a “summary order” filed Thursday, the 2nd U.S. Circuit Court of Appeals rejected Thomas’ claim that U.S. District Judge Janet Bond Arterton erred in excluding certain evidence Thomas sought to introduce at his 2013 trial.

Thomas, who claimed Arterton abused her discretion and violated his due process rights, had asked that he be granted a new trial.

Arterton ruled Thomas could not present evidence that he previously had reimbursed the tribe for personal expenses he charged to a tribe-issued American Express card and that other tribal councilors had used such cards to pay for personal expenses.

“We find no error in the District Court’s evidentiary rulings, much less an ‘abuse of discretion,’” the appeals court said in its order. A three-judge panel consisting of John Walker Jr., Jose Cabranes and Raymond Lohier Jr. heard Thomas’ appeal Oct. 21 in New Haven, the scene of Thomas’ trial.

Neither Thomas’ attorney, Steven Rasile of West Haven, nor a spokesman for the U.S. District Attorney’s office in Connecticut would comment on the appeals court’s order.

The order notes that while Thomas conceded that the intent to repay funds is no defense to charges of theft or embezzlement, he contended that his history of reimbursing the tribe for personal expenses he charged to his American Express card showed “he lacked the requisite intent to commit the crimes with which he was charged.”

Thomas also claimed that another tribal councilor had charged personal expenses and then reimbursed the tribe, showing that the tribe allowed such activity in practice even though a written tribal policy prohibited it.

“Such evidence would only have been relevant at trial if Thomas’s conduct comported with that practice,” the order says. “Here, it is undisputed that Thomas did not reimburse the Tribe for any of the over $100,000 in personal expenses that he charged to his card between October 2007 and September 2009 — despite the fact that he was not indicted until January 2013.”

Thomas, who served as the tribe’s chairman from 2003 to 2009, was convicted last November. He began serving his sentence in January.

b.hallenbeck@theday.com

Twitter: @bjhallenbeck