SET executive vice president Suthichai Chitvanich said the findings of his agency's investigation had been forwarded to the Securities and Exchange Commission (SEC).

"There have been no irregularities in trades in Shin or AIS by directors, executives, individuals who hold more than 5 per cent in the two companies, or by any state officials," he said.

Somprasong Boonyachai, chief executive officer of AIS, and Yingluck Shinawatra, the mobile-phone company's former president, were earlier mentioned as executives who could have benefited from inside information concerning Shin's takeover by Singapore's Temasek Holdings. Both sold their shares while rumours were rampant that Shin was to be acquired by a foreign investor.

The SET investigation looked back 30 days before the January 23 announcement of the takeover deal. During that period, there was significant trading in the two companies, and traders could be divided into two groups.

The first group involved individuals whose transactions accounted for 10 per cent of the total turnover of Shin share trading.

"However, the investigation found that no individual was found to be connected to the company's directors or executives."

The second group concerned trading by foreign institutions. Their trade also accounted for 10 per cent of the total turnover of Shin share trading.

"However, we're not empowered to investigate their relationships with the company's directors or executives," said Suthichai. "The SEC would be in a better position to look into this issue."

Suthichai also confirmed Somprasong and Yingluck's explanations that their sales of AIS shares were in accordance with the exercise of warrants issued under the employee stock-option programme. He said that as the warrants could be exercised from 2003-06, the SET found that the recipients had regularly sold their shares, each in small amounts.

"The executives' share sales were a point of concern to the exchange, because they occurred prior to the announcement of the Shin takeover deal. But our investigation found the sales to be in line with their warrant exercises. We found no one who had made use of inside information," he concluded.

Siriporn Chanjindamanee

The Nation