Adds FTI spokesperson's quotes and comments in paragraphs 3, 6, 8 and data on car sales and exports from paragraph 3

BANGKOK, Feb 24 (Reuters) - Car production in Thailand fell a surprisingly large 24.63% in January from a year earlier to 107,103 units due to weak domestic sales and exports, the Federation of Thai Industries said on Monday.

Thailand is Southeast Asia's biggest autos production centre and an export base for some of the world's top automakers, including Toyota 7203.T and Honda 7267.T.

"I was very shocked. The production numbers are really low," Surapong Paisitpattanapong, spokesperson for the FTI's automotive industry division, told a news conference.

The output fall was larger than the 17.37% year-on-year drop in December, and was the 18th straight month that production had declined.

Domestic car sales dropped by 12.26% in January from a year earlier to 48,092 units, after a drop of 20.94% in the previous month, weighed down by tightened auto loans due to high household debt, the federation said.

Exports tumbled 28.13% in January from a year earlier to 62,321 units, the lowest in 33 months, due to increased competition from Chinese cars, compared with a drop of 15.46% in the previous month, Surapong said.

Australia, the Philippines and Japan were Thailand's top three car export markets last year.

The federation will closely monitor expected government measures to help with auto loans as well as the United States' policy on auto tariffs, he said.

Earlier this month, U.S. President Donald Trump said levies on automobiles would come as soon as April 2.

(Reporting by Thanadech Staporncharnchai; Writing by Orathai Sriring; Editing by John Mair and Muralikumar Anantharaman)

((orathai.sriring@tr.com;))