The Securities and Exchange Commission has suspended Asia Wealth Securities Co from doing business for alleged use of clients' money without their consent.
The SEC said on Friday that the Stock Exchange of Thailand had therefore suspended trading in stocks through AWS. It recommended AWS clients transfer their stocks to accounts with other securities firms so they can resume trading.
The SEC said that the order concerned only AWS and did not have any impact on other securities firms.
On Thursday the SEC said that AWS had spent money from clients' accounts on unauthorised share purchases. The money amounted to 157.99 million baht.
The SEC said this could cause great damage to clients and ordered AWS to return the money by Sunday. The suspension order would reman in effect until the money was returned.
The SEC's move followed the start of an investigation into suspicious trading in the shares of More Return Plc (MORE), a company officially said to do business in the energy, water and property sectors.
Trading in MORE was suspended on Monday after the Stock Exchange of Thailand noticed suspicious trading of its shares on Thursday and Friday, Nov 10-11.
Other agencies including the Anti-Money Laundering Office are involved in the investigation. The irregular trading caused damage estimated at more than 4.3 billion baht to several brokers.
The SET has requested MORE's board of directors to provide clarification and information about the suspicious transactions and submit relevant documents within seven days from Nov 17, along with information disclosure through the bourse's information system.
The SET noticed irregularities on Nov 10 when trading in MORE stock exceeded 7.14 billion baht, the highest on both the main exchange and the Market for Alternative Investment.
MORE shares opened at 2.90 baht on Nov 10, up 4.3% from prior trade, then declined to a floor of 1.95 baht.
The price continued to decline the next day to 1.34 baht, at which point the SET notified investors to trade with caution and required brokers to increase supervision of trading of such securities.
Most of the purchase orders reportedly came from a major shareholder of the company, with the sales also coming from the same person.
It was reported that many securities firms were affected because they did not receive money for purchase orders for MORE but had to pay the seller.
SET president Pakorn Peetathawatchai on Friday declined to say whether the suspension order against AWS was related to the MORE investigation. He said he did not know how AWS spent the money from clients' accounts.
He said police and the Anti-Money Laundering Office were investigating the issue following complaints from damaged brokers.
On Wednesday representatives of 11 securities firms asked the Economic Crime Suppression Division to investigate people involved in the unusual trading of MORE shares.