Vudhigorn Suriyachantananont, executive vice president of TMT, said that despite the measures, lingering concerns in global volatity would put pressure on private investment. Meanwhile, domestic purchasing power remains low.
In January, sale amounted to 51,821 units, a 13.2 per cent decrease from the same month a year earlier, according to data compiled by the company.
Of total, passenger cars accounted for 16,384 units, down by 30 per cent on year.
Commercial vehicle sale declined by 2.4 per cent to 35,437 units. In this category, 29,000 one-tonne pickup trucks were sold, showing a 0.9 per cent increase.
TMT attributed the contraction to slow recovery in the domestic economy as well as low agricultural product prices. Some buyers also completed deals before the end of 2015, before the effectiveness of new excise tax structure.