The moderator of an Internet forum in the Gulf Arab state of Oman said on Tuesday he was sentenced to one month in jail and fined 200 rials ($519) for publishing a cabinet directive on the Web.

Diplomats say the case is a sign that Oman, which is trying to attract foreign investment, wants to put restrictions on new media such as the Internet.

Ali al-Zuwaidy, a civil aviation official, used the popular forum Sablat Oman last year to publish the directive, which ordered a halt to live radio programs where members of the public are free to phone in and criticize public figures.

He used a pseudonym, but security authorities were able to track him down.

Omani officials were not immediately available to comment. Omani media have not reported the case but the verdict was carried by other Arab media.

Oman, a country of 3.3 million people on the tip of the Arabian peninsula, has one of the most closed media and political cultures in the Gulf region, analysts say. But the restraint of the traditional media has helped the Internet become a popular arena for discussion.

Zuwaidy told Reuters he must only serve 10 days of the one-month sentence, plus 20 days of community service. As he spent 11 days in jail in January, he is able to walk free.

He said he was acquitted in a second case where he was accused of insulting the former head of state telecom operator Omantel, Mohammed al-Wohaibi, by allowing a Web forum contributor to publish critical comments about the management of the firm.

(Writing by Andrew Hammond, editing by Mark Trevelyan)

($1=.3850 Omani Rial)