BANGKOK - Thai rice prices, which have jumped almost 9% since Manila launched its first import tender in October, are likely to extend gains on strong demand for the staple, traders and exporters said on Tuesday.

Although Thai exporters are likely to win only a small portion of 1.8 million tons sought by the Philippines, huge demand from Manila and a poor crop in dought-hit India are expected to push benchmark Thai prices higher.

Thai exporters are likely to be awarded only 15%, or some 300,000 tons, of the total Manila wants to buy through 3 tenders in December, said Chookiat Ophaswongse, president of the Thai Rice Exporters Association.

Traders said Vietnam was expected to be the big winner due to its competitive prices and close rice trade relationship with Manila. That means the potential rice supply from Vietnam would drop sharply, resulting in higher global prices.

"Thai rice prices should rise just like Vietnamese prices in December," said Chookiat.

Thailand's benchmark 100% B white rice stands at $565 a ton, up from $520 in mid-October shortly after Manila announced its first tender for 2010. The grade had nearly trebled to a record $1,080 in April 2008, driven by a series of Philippine tenders and export curbs by key producers.

The Philippines, the world's biggest rice importer, has set 3 tenders for Dec. 1, 8 and 15, aiming to buy 600,000 tons in each to boost supplies after storms pulverised output.

Vietnamese 25% broken grade rice has risen to $470 per ton from around $420 in early November and is likely to rise further in December, traders said.

There would then be a knock-on effect on Thai prices.

"Most buyers will have to turn to Thailand, the only key supplier in Asia with ample rice for sale," an exporter said.

That would support the price of the same 25% broken grade white rice in Thailand, which was very close to Vietnamese levels this week due to the impact of the Manila tenders.

Rising prices of low-quality 25% broken rice would help push up other grades, including the benchmark 100% B grade white rice, exporters said.

"Thai rice prices are expected to go through a consolidation phase after the Philippine tenders," said Kiattisak Kanlayasirivat of Novel Agritrade Co. Ltd.

The rise in Thai rice prices is also partially due to the government's intervention scheme.

For the current crop, the government has implemented a new scheme under which farmers are paid the difference if they sell rice below a guaranteed 10,000 baht ($300) per ton, but it has also maintained its old-style program, with the state buying rice directly from farmers to support prices.