The Philippines, the world's biggest rice buyer, said Wednesday high bids from suppliers at this week's rice tender meant it may award only 500,000 to 520,000 tons of the grain, below its specified import volume.

The National Food Authority drew sharply higher price offers at a tender for a record 600,000 tons of rice on Tuesday, indicating bidders anticipated a further spike in prices.

The lowest bid at Tuesday's tender, from Vietnam's top rice exporter, Vinafoood 2, was $598 a ton, up nearly 28 percent from the lowest offer of $468.50 a ton at Manila's previous rice tender on Nov. 4.

''Based on the price offers, we can award around 500,000 to 520,000 tons,'' Romeo Jimenez, NFA director, told reporters.

''From their bid prices, we cannot afford it,'' Jimenez said when asked why a full award from Tuesday's tender was not possible.

Of the volume to be awarded, 300,000 tons could go to Vinafood 2, while the rest can be taken up by Thai suppliers, he said.