It was the second defamation conviction in two days against outspoken media tycoon Sondhi Limthongkul. He was freed on bail in both cases, pending appeals.

The Appeal Court upheld a guilty verdict against Sondhi for defaming Phumtham Wechayachai, former deputy transport minister and a political ally of ousted Prime Minister Thaksin Shinawatra.

Sondhi spearheaded protests against Thaksin that preceded the 2006 coup that toppled him. He also led months of demonstrations against Thaksin's allies who later came to power.

In April, Sondhi _ who founded the "yellow shirts" People's Alliance for Democracy movement _ survived an assassination attempt after assailants sprayed his car with bullets.

A court statement said Sondhi accused Phumtham of having sympathy with the Communist Party of Thailand in his student days and that he was disloyal to the country's revered constitutional monarchy. The statement was made during a political talk show in 2005.

In another defamation lawsuit, the Bangkok Criminal Court sentenced Sondhi to two years in prison Thursday for defaming former Finance Minister Pridiyathorn Devakula. Sondhi accused Pridiyathorn of attempting to whitewash corruption allegations in favor of Thaksin's allies.

"I will appeal the cases," Sondhi told reporters. "I have been through assassination attempts and worse things. Prison is not something I fear."

Since 2005, Sondhi has used his media empire and influence to organize the anti-Thaksin movement, which last year occupied the prime minister's office for several months and then shut down the capital's two airports for a week.

Sondhi is also under investigation for the weeklong occupation of Bankgok's airports, which stranded some 300,000 travelers. So far, no one has been prosecuted.