The four-month trial of Naji Hamdan also was carried out without making public details of the accusations _ showing the tight lid on information over security matters in a nation that promotes itself as the West's foothold in the Gulf.
Anti-terrorism laws in the Emirates, passed in the aftermath of the 2001 U.S. terrorist attacks, have been often expanded to muzzle political dissent and have drawn sharp criticism from international rights groups.
The court sentenced Hamdan, an American of Lebanese origin, to 18 months in prison after facing three terrorism-related charges, including having ties an al-Qaida group in Iraq. But Hamdan _ who denied the allegations _ should be freed soon because the sentence takes into account the time he spent in custody since his arrest here last year.
Once he serves his time, Hamdan is to be deported from the country.
Hamdan's lawyer, Abdul Khader al-Haithami, claimed in an earlier hearing that his client suffered torture and threats in detention and was forced to sign a confession "to whatever they wanted to hear."
The case is a "classic example" of problems associated with state security and terrorism-related trials around the region, said Deborah Manning, a senior legal officer with Al Karama, a Geneva-based and Arab world-focused human rights organization.
"Serious allegations are often not backed by proper evidence," Manning said. "Heavy reliance on secret information severely prejudices the proper defense."
In his verdict, chief justice Khalifa al-Muhairi gave no details on his decision such as whether the 43-year-old Hamdan was convicted of all three charges. There are no appeals to verdicts by the UAE's Federal Supreme Court.
"I'm disappointed because I was not acquitted," Hamdan told The Associated Press as he was led away by security forces after the verdict.
Rights groups, including the American Civil Liberties Union, also have accused U.S. authorities of pushing the case in the Emirates because they lacked enough evidence for American courts. The ACLU asked a U.S. court to press for a halt to the case, but a U.S. judge ruled in August that there was no authority to interfere in a foreign criminal prosecution.
"The security system in the UAE is very powerful," said Abduldkhadi al-Khawaja, a Bahrain-based coordinator for Frontline, an international group that protects human rights activists. "Their activities are not related only to terrorism, but any kind of political activism, including defending human rights."
Political parties are not allowed in the UAE and associations for the promotion of civil liberties and human rights are closely controlled. Leading lawyers, university professors and activists have been detained and questioned by security services, rights groups say. Some have been fired from their jobs, others have been banned from public life after they were released from detention without ever being charged with any crime.
Hamdan said he was not politically active after he moved with his family back to the Middle East in 2006 after living in the United States for almost 20 years. He was an active member of the Islamic community in the Los Angeles area, where he ran a successful auto parts business.
He said the FBI began questioning him about whether he had terrorist ties in 1999. He was never charged with any crime in the United States.
He was arrested in the UAE in August 2008 and charged in June 2009 with supporting terrorism, working with terrorist organizations and being a member of a terrorist group. After his arrest, he wrote a note to a U.S. diplomat _ which was later obtained by the AP _ saying he was subjected to beatings, threats tohis family and verbal abuse.
The U.S. Embassy in the Emirates had declined to comment on the case except to say that Hamdan has been given consular support. U.S. officials in the UAE declined to comment on the verdict.