A patient is evacuated from a hospital in a flooded area in Thailand's Ayutthaya province Oct 9, 2011. Thailand's Department of Prevention and Mitigation said on Sunday at least 261 people have been killed and four are still missing due to the flooding which started in mid July. [Photo/Agencies]

BANGKOK - Nearly 200 factories, including one run by Japanese car maker Honda Motor Co Ltd , closed in the central Thai province of Ayutthaya because of flooding, which could threaten Bangkok this week, officials said on Sunday.

About 261 people have died since late July in flood-related incidents, the Department of Disaster Prevention and Mitigation said. Some 2.3 million people have been affected in the worst flooding to hit parts of Thailand in 50 years, mainly in the centre, north and northeast.

On Thursday the Center for Economic and Business Forecasting, part of the University of the Thai Chamber of Commerce, cut its forecast for gross domestic product (GDP) growth this year to 3.6 percent from 4.4 percent because of the floods.

It put the impact of the flooding at between 1.0 and 1.3 percentage points of GDP and said its new growth forecast would have been lower but for recent strength in exports.

The commerce ministry said on Friday it had slashed its forecast for the main rice crop, which farmers are just starting to bring in, to 21 million tonnes from 25 million because of the flooding.

Thailand is the world's biggest rice exporter. The crop damage will add to the pressure on export prices, already being forced up by the high buying price set under a government intervention scheme aimed at helping poor farmers.

Bangkok Governor Sukhumbhand Paribatra said in a statement the authorities were preparing an evacuation plan to move people from affected areas if floods hit the capital, much of which is just two metres above sea level.