SEOUL (Reuters) - A South Korean court on Thursday sentenced the head of the company that operated a ferry which capsized in April to 10 years in jail over his role in the country's worst maritime disaster in decades.

Kim Han Sik, the chief executive of Chonghaejin Marine, was found guilty of negligence causing death and embezzlement. His sentence was the toughest penalty handed down to anyone other than the ferry's crew over the deaths of 304 passengers, most of them teenage children. Only 172 of the ferry's 476 passengers and crew were rescued.

Kim apologised to the families of the victims but said last month that he was simply a paid employee of the company and the decisions that led to the disaster were made by the firm's de-facto owner, Yoo Byung-un, media reports said.

Yoo, who was the head of the family that owned a holding company at the centre of a network of business interests that included the ferry operator, was found dead in June.

The overloaded Sewol capsized while making a turn on a routine voyage to the holiday island of Jeju. The vessel was later found to be defective, with additions made to increase passenger capacity making it top-heavy and unstable.

The court found other executives of the firm to three to six years in prison for negligence and embezzlement. The officials were guilty of knowingly operating the ferry that was dangerous, and there was "considerable causal relationship" between their jobs and the disaster, the court said.

The 15 surviving crew members including the captain were convicted last week on negligence charges and sentenced to between five and 36 years in jail.