Iran is reportedly seeking to buy at least 100,000 tonnes of Thai rice and Bahrain 40,000 tonnes of Hom Mali rice under government-to-government deals.

"Purchase orders have yet to be confirmed, but this is a good sign for Thailand's rice exports," said Chookiat Ophaswongse, the president of Thai Rice Exporters Association. "We've also heard there are purchase orders from Libya, which has never bought Thai rice."

Iran bought a total of 650,000 tonnes of 100% white rice from Thailand last year, while Bahrain bought 4,000 tonnes including Hom Mali, white rice, broken rice and parboiled rice.

Iran bought 74,000 tonnes of Thai rice during the first half of this year.

Mr Chookiat projected that exports would be more promising in the second half of the year, particularly after Vietnam announced plans to impose an export tax on rice.

Hanoi said last week it planned to impose export duties on rice of up to $176 per tonne, which would push its rice export prices up to a range of $800 to $1,300 depending on the grade.

The export duties are imposed less than a month after Vietnam lifted a ban on signing new export contracts.

"Hanoi's export duties would definitely benefit Thai rice exports, as such measures would make Hanoi rice prices costlier," he said. "That will allow us to ship more rice, as the markets which used to buy rice from Vietnam such as Africa and Iraq and Iran will shift to buy more rice from Thailand."

Thailand could thus export more than 10 million tonnes of rice this year, he added.

In July, according to Mr Chookiat, rice exports were estimated at 940,000 tonnes, bringing the seven-month total to about seven million tonnes.

Thailand, the world's biggest rice exporter, shipped 9.5 million tonnes in 2007, and had expected to export a similar amount this year.

The country shipped a record 10.13 million tonnes of rice in 2004.