This year's survey by the Political and Economic Risk Consultancy showed perceptions of corruption improved sharply in China and Thailand and slightly in several other countries compared to their last poll in 2003.

Using a scale with zero the best possible grade and 10 the worst, PERC asked more than 1,000 expatriate businessmen and women in the region to rate how bad they viewed the problem of corruption in the country where they are working, as well as in their home countries.

Singapore was voted the least corrupt country with a score of 0.50, although this was a slight deterioration from its grade of 0.38 last year.

Japan was at a distant second with 3.50, and Hong Kong was in third place with a score of 3.60.

Taiwan came in fourth with a grade of 6.10 and South Korea followed with 6.67.

China, Malaysia, and Thailand were tied at sixth place with scores of 7.33, trailed by the Philippines at 8.33 and Vietnam at 8.67.

India, with a score of 8.90, and Indonesia, which got a grade of 9.25, rounded up the worst performers.

For comparison, the survey included the United States, which got a grade of 2.45 while Australia had 2.17.

"Perceptions have improved in the past year in the majority of Asian countries covered by our survey of expatriate businessmen conducted in January and February of this year," the Hong Kong-based risk consultancy said.

China's score improved one point from last year, and Thailand's grade was better by 1.42 points.

Although the worst, Indonesia's grade was an improvement from last year's 9.33.

Manila's score worsened by 0.66 points.

Malaysia's grade also sharply deteriorated from 6.00 to 7.33.

But PERC clarified this was largely due to the willingness of the government under Prime Minister Abdullah Badawi to admit that the problem of corruption exist, compared with the rule of former prime minister Mahathir Mohamad.