BANGKOK Thailand's manufacturing production index (MPI) in April contracted by a more-than-expected 8.14% from a year earlier, as exports slowed and production costs rose, the industry ministry said on Wednesday.

The figure compared with a forecast in a Reuters poll for a fall of 2.15% in April, and came after March's revised 3.86% year-on-year drop.

In the January-April period, the MPI declined 4.69% from a year earlier, the ministry said in a statement.

The ministry forecast factory output would show zero to 1% growth this year, the ministry said.

While exports remain sluggish, domestic demand has increased, driven by strength in the vital tourism sector and higher investment, it said.

Industrial goods account for about 80% of total customs-based exports, which contracted by a more-than-expected 7.6% in April from a year earlier.

(Reporting by Orathai Sriring, Satawasin Staporncharnchai; Editing by Kanupriya Kapoor)