The bidding drew an active response from potential buyers, although the offers fell short of the reference prices set by the Commerce Ministry.
Duangporn Rodphaya, director-general of the Foreign Trade Department, said 46 small, medium-sized and large exporters, millers and rice packers submitted bids yesterday.
But the department has yet to secure any deals with buyers, as most of them proposed prices below the reference prices set by the panel handling rice sales. The reference prices were not disclosed.
The bidders were set to make offers again yesterday evening. In the event that no bidder offers prices on par with the reference prices, the department is prepared to present the bidders who offer the highest prices to the panel for consideration.
Ms Duangporn said her department had yet to specify when the next auction would be called.
"The next auction will rely on the panel's consideration," she said. "But certain conditions may be adjusted to make it more enticing."
Charoen Laothamatas, president of the Thai Rice Exporters Association (TREA) and who observed yesterday's bidding, said the auction was the best option and transparent, not to mention well timed to benefit from strong demand and competitive Thai prices.
"Thai 5% white rice right now is fetching an average of US$450-460 a tonne compared with as low as $380-390 a tonne under the previous government, while the paddy market price is now 8,500 baht a tonne compared with 7,000 baht," he said.
"This reflects high demand in the market, and the state rice auctions are unlikely to have a large effect on the current market prices."
He suggested the authorities speed up rice sales on a continuous basis in lots of up to 200,000 tonnes before any new supply enters the market.
TREA honorary president Chookiat Ophaswongse said Thai rice exports had become more promising with higher demand and price competitiveness.
"Right now is considered a good opportunity for Thai rice, as the market is in short supply after Vietnam beefed up its cross-border shipments to China," he said.
The Philippines is also due to call a bid to buy a new lot of 500,000 tonnes of rice on Aug 27.
Mr Chookiat urged officials to offer financial support to the Thai bidders.
Thailand can expect to export 9 million tonnes of rice at best this year, given the limitations of a labour and freighter shortage, he said.
The military regime last month vowed to sell an average of 500,000 tonnes a month from existing state rice stocks and dispose of the existing 18-million-tonne surplus within three years through four channels.
Those channels are general auctions, government-to-government sales, direct sales and the Agricultural Futures Exchange of Thailand.