Thailand's manufacturing production index (MPI) in October fell 8.45% from a year earlier, dragged down by lower production of cars, petroleum and steel, the industry ministry said on Wednesday.
That compared with a forecast of a 4.95% drop in a Reuters poll and September's revised 5.06% decline.
Capacity utilisation was at 62.83% in October, compared with September's revised 63.80%.
The ministry forecast is that the MPI will drop 3.8% this year and increase 2%-3% next year.