GENEVA, Sept 10 (Reuters) - A Swiss criminal court convicted Kuwait"s Sheikh Ahmad Al-Fahad Al-Sabah, a power broker in international sports, of forgery on Friday in a trial over whether he used a bogus Kuwaiti coup plot to gain advantage over political rivals. A member of Kuwait"s ruling family and a former OPEC secretary-general, Sheikh Ahmad listened with bowed head and clasped hands as his translator read out the 30-month jail sentence, half of it suspended. He will appeal the verdict. Sheikh Ahmad had denied all the charges in the case, which has divided the Kuwaiti ruling family and prompted him to step back from some of his public sporting roles, including membership of the International Olympic Committee. He decided on Friday to step down also as president of the Olympic Council of Asia, where he was completing an eighth term. "I believe I am innocent," he told reporters outside the Geneva courtroom, adding that he was "100 percent" sure he would return for the appeal. His office later said in a statement that Sheikh Ahmad was "confident" that he would clear his name. The criminal fraud case was launched in Switzerland in 2015 as one of the sheikh"s co-defendants was, at the time of the alleged coup plot, a Geneva-based lawyer who acted for him. The sheikh was one of five defendants in the trial, all of whom were convicted and one with a heftier sentence of 36 months. They were not named for legal reasons. read more "We are satisfied. The court has mostly decided in our favour," said lawyer Pascal Maurer, who acted on behalf of one of the plaintiffs. VIDEOS The case had revolved around videos purporting to show former prime minister Sheikh Nasser al-Mohammed and the former speaker of parliament, Jassem al-Kharafi, plotting to overthrow Kuwait"s then-emir. Prosecutors alleged that Sheikh Ahmad knew that the videos, which he passed on to Kuwaiti authorities, were fakes. Sheikh Ahmad told the court last week he had submitted the videos to Kuwaiti authorities believing, at the time, that they were authentic. In 2015, he publicly apologised in a statement via Kuwait TV to the Emir of Kuwait, to Sheikh Nasser, Al-Kharafi and their families for his role in the affair, saying he had thought the videos were genuine and credible. The court also ordered on Friday that one of the unnamed defendants in the case, a British former lawyer of the sheikh, receive psychotherapy.