Prices of parboiled rice from top exporters climbed this week, fuelled by limited supplies, pushing Vietnamese rates to their highest in more than 15 years, and in turn driving up the less expensive Indian variety to its highest in two months.

Vietnam's 5% broken rice RI-VNBKN5-P1 was offered at $660 to $665 a metric ton on Thursday, its highest since mid-July 2008, versus $655 to $660 last week.

"Prices edged higher on tight supplies," said a trader based in Ho Chi Minh City.

Preliminary shipping data showed 162,800 tons of rice to be loaded at Ho Chi Minh City port from Dec 1 to 20, with most of it heading to Indonesia, the Philippines and Cuba.

The prices of India's exports rose in line with the upward trend in other exporters and concerns over production.

India's 5% broken parboiled variety RI-INBKN5-P1 was quoted at $505 to $512 a metric ton this week, its highest in two months, up from last week's range of $499 to $506.

"Due to widening gaps between Indian prices and those of other countries, buyers are now willing to accept higher prices," said an exporter in the eastern city of Kolkata.

India's rice output is expected to fall this year, for the first time in eight, making it more likely that New Delhi will extend export curbs to hold down prices ahead of general elections due next year.

The price of Thailand's 5% broken rice RI-THBKN5-P1 increased to its highest since August, at $646 to $650 a metric ton, from last week's $640.

Traders said the increase was fuelled by more orders from the Philippines this week.

Prime Minister Srettha Thavisin said Indonesia told the Thai government of its intent to buy 2 million metric tons of the grain in a letter received on Monday.

Supply has dwindled and traders say they expect more entering the market early next year.