By Mai Nguyen, Patpicha Tanakasempipat and Rajendra Jadhav

HANOI/BANGKOK/MUMBAI, March 30 (Reuters) - Rice prices firmed in Thailand and India on stronger local currencies, while prices weakened in Vietnam as the country entered its peak harvest season, traders said on Thursday.

India's 5 percent broken parboiled rice prices rose by $2 per tonne to $373 to $378 a tonne this week, as gains in the rupee led exporters to raise prices. The rupee was near its highest level in about 18 months.

"In dollar terms we have raised prices due to a rising rupee. Our realisation in rupee terms is still down compared with last month," said an exporter based at Kakinada in the southern state of Andhra Pradesh.

India, the world's biggest rice exporter, mainly exports non-basmati rice to African countries and premier basmati rice to the Middle East. Its rice production is likely to rise by 4.3 percent to a record high 108.86 million tonnes in 2016/17.

"African buyers are making inquiries but still demand is weak," said another exporter based at Kakinada.

In Thailand, the world's second largest rice exporter, prices of the benchmark 5-percent broken rice rose to $350-$365 a tonne free-on-board (FOB) Bangkok from $350-$362 last week, as the baht appreciated against the U.S. dollar, but demand has been lacklustre.

"The baht keeps strengthening, but actual rice prices haven't moved up that much," said a Bangkok-based trader.

The U.S. dollar/Thai baht FX spot rate was at 34.49 as of 0615 GMT on Thursday, compared with the closing figure of 34.58 a week earlier, Thomson Reuters data showed.

The Thai government held a state auction last week to offload spoiled rice for industrial use, but results have yet to be announced.

"Thai rice market has been quiet for the past three months. Nothing spectacular, just regular orders," said an exporter in Bangkok.

Vietnam, the world's third largest rice exporter, has entered its main harvest season since late March, pushing down prices of the 5 percent broken rice to $348-$350 a tonne FOB Saigon from $350-$355 last week, traders said.

"Prices are down because of the harvest season but we still can't sell due to competitive Thai prices... Most of the shipments now are still for China," said a Ho Chi Minh City-based trader.

Vietnam's rice exports are expected to fall 23.9 percent annually to 1.19 million tonnes in the first quarter, after its shipments of the grain dropped 26.5 percent in 2016 due to lower production caused by climate changes, the government said.

Traders said the market was eyeing potential deals from the Philippine government, one of Vietnam's biggest rice importers, but the Philippines' farm minister said there might be no urgent need for a 250,000-tonne rice import plan.

(Reporting by Mai Nguyen in Hanoi, Patpicha Tanakasempipat in Bangkok and Rajendra Jadhav in Mumbai; Editing by Subhranshu Sahu) ((mai.nguyen@thomsonreuters.com; +844 3825 9623; Reuters Messaging: mai.nguyen.thomsonreuters.com@reuters.net))