A federal appellate court has ruled that a Canadian man who says American officials sent him to Syria to be tortured cannot sue America.

Maher Arar, a native of Syria, was on an American terror watch list because Canadian law enforcement officials had told their American counterparts that they believed Mr. Arar had ties to Al Qaeda, according to a report by a Canadian commission that investigated Mr. Arar’s case.

Immigration officials detained Mr. Arar at John F. Kennedy International Airport in 2002. Mr. Arar was then forcibly transported to Syria, where he says he was held in a small cell and beaten repeatedly. Syria released him in 2003.

The Canadian commission subsequently found that Mr. Arar poses no security threat; in compensation, Canada has paid him close to $11 million.

Mr. Arar’s lawsuit against America, which accuses the country of outsourcing torture, was first dismissed in 2006 by a federal judge in Brooklyn. Yesterday, the 2nd U.S. Circuit Court of Appeals affirmed the dismissal.

In a statement forwarded by his lawyers at the Center for Constitutional Rights, Mr. Arar called the ruling “outrageous,” adding: “It basically legitimizes what was done to me, and permits the government to use immigration law as a disguise to send people to torture without regard for due process.”

The majority opinion, written by Judge José Cabranes, concluded that Congress has not allowed “inadmissible aliens” to sue American officials for making decisions leading to their deportation. Mr. Arar’s suit names former top Bush administration officials, including Attorney General Ashcroft, as well as the current FBI director, Robert Mueller, as defendants.

In a dissent, Judge Robert Sack said the majority was mistakenly treating Mr. Arar’s suit as an ordinary immigration case.

The majority, Judge Sack wrote, mischaracterized it “as an immigration case, when it is in fact about forbidden tactics allegedly employed by United States law enforcement officers in a terrorism inquiry.”

But Judge Cabranes, who was joined by Judge Joseph McLaughlin, said there was no basis in the law for letting the case go forward.

“Whatever the emotive force of the dissent’s characterization of the complaint, we cannot disfigure the judicial function to satisfy personal indignation,” the majority wrote.

A spokesman for the Justice Department, Charles Miller, said in a statement that Mr. Arar’s deportation was lawful. “The U.S. government received assurances from Syria that he would not be tortured,” he said.