Thailand's manufacturing production index (MPI) contracted for a ninth straight month in January, down 4.59% from a year earlier, hit by lower production of cars, sugar and palm oil, the industry ministry said on Wednesday.
The performance was worse than a forecast drop of 3.9% in a Reuters poll, and followed December's decline of 4.35%.
Capacity utilisation in January was 66.48%, up from a revised 64.02% in December.
In January, production of cars fell 12.8% from a year earlier while sugar dropped 15.2% and palm oil tumbled 40.7%, the ministry said.
But production of hard disk drives rose 13.5% last month year on year and air conditioners jumped nearly 22%.
The ministry expects the coronavirus outbreak, which originated in China and spread to more than two dozen countries, to have a short-term effect on Thailand's manufacturing output, mainly on the food industry, due to a drop in tourists, Thongchai Chawalitpichaet, head of the ministry's Office of Industrial Economics, told a news conference.
The Tourism Authority of Thailand previously said the number of foreign tourists might fall by 5 million to around 35 million this year as the virus outbreak has raised fears of a pandemic.
However, a weaker baht and higher production of health products should lend support, he said.
"So, the overall picture should be positive," Mr Thongchai said, adding February's output was expected to be similar to January's level.
The ministry has forecast the MPI will rise 2% to 3% this year after last year's 3.7% contraction.