Exports were 229.5 billion dollars, up 3.1 per cent from 2011, slower than that year's 17.2-per-cent export growth from the previous year, according to the ministry's year-end figures.
The deficit was larger than 2011, when the trade balance was a 334-million-dollar surplus, which was equivalent to a 77-billion-baht (2.6-billion-dollar) deficit due to currency fluctuations.
In 2012, exports of agricultural goods declined 10.8 per cent, led by rice shipments which fell 28.0 per cent.
The government implemented a price-support scheme for rice farmers last year, paying 15,000 baht per tonne of plain unhusked rice, but making Thai rice uncompetitive on the global market.
Thailand was displaced from its three-decades-old rank as the world's leading rice exporter by India and Vietnam, ranked first and second, respectively, for 2012.
Imports in 2012 were 247.6 billion, up 8.2 per cent year-on-year.//DPA