BANGKOK. .July 6: Thailand's Supreme Court has upheld the acquittal of 12 prominent investors on charges of manipulating the sock price of a scandal-plagued bank, local papers reported Saturday, according to AP.

The acquittal of Song Watcharasiriroi. also known as Sia Song, and his associates was a setback for the Securities and Exchange Commission in' its efforts to combat insider trading and make Thailand's financial markets more transparent.

Song, who was described by The Nation newspaper as the country's "most powerful investor. able to sway the stock market by the enormous (share) volume under his command." was accused of conspiring with colleagues to amass a 34 per cent stake in the troubled Bangkok Bank of Commerce in 1992.

Their alleged intent was to drive up the share price before dumping the stock. The bank was recently taken over by the finance ministry, and its executives are facing embezzlement charges.

They are accused of ringing up nearly three billion dollars in bad loans to themselves and

a group of powerful politicians.

The Supreme Court decided that Song was simply buying the shares for his own accounts under normal trading conditions and so a conspiracy was not proved.

"I don't want to criticise the SEC." a smiling Song told The Nation after his acquittal. "But the case has created enormous damage to the system.”

In an interview with the Bangkok Post. Sfbck Exchange of Thailand President Singh Tangtatswas compared the case with the US trial of OJ Simpson, saying that the system had failed by not punishing Song.

Song's troubles with the law have not completely ended. He ^nd his associates still face stock manipulation charges delaying with three other companies.

Stock market observers told local papers, however, that if the Supreme Court didn't convict Song in this case, it probably won't convict him in future cases.

One stock analyst told the Bangkok Post that use of insider information on the Thai bourse will surely continue and Is getting more sophisticated all the time.