Imports dipped 0.2 percent in January from a year before, leaving a trade deficit of $0.6 billion, ministry economist Boonchai Charassangsomboon told a news conference, saying that was based on preliminary data from the Commerce Ministry's customs department.
The official customs data is normally published around the 20th to the 22nd of each month but it has been postponed this month, with officials blaming data system changes.
Flooding in the second half of last year hampered agricultural production before devastating central industrial provinces from October.
As a result, exports fell 12.4 percent in November from a year before but they were only down 2 percent in December.
Imports rose 19.1 percent in December, when firms rushed to bring in new machines and material to replace those damaged by the floods.
"The small growth in January exports reflected signs of recovery in the manufacturing sector," Boonchai said.
Industry Ministry data on Monday showed factory output slid by 15.2 percent in January from a year before but that was better than the revised 25.3 percent drop in December. Some flood-hit factories have still not reopened.
"Output should turn positive late in the second quarter as some firms have resumed production," Aphiwat Asamaporn, deputy head of the Office of Industrial Economics, told reporters.
The flooding hit the auto and electronics sectors the hardest as Thailand is Southeast Asia's biggest auto maker and the world's second-biggest maker of hard disk drives. Many of the flood-hit firms are big exporters in those sectors.
Exports are equal to more than 60 percent of GDP each year. Industrial goods account for about 65 percent of total shipments and agricultural products 17-19 percent.
Boonchai said the overall economy also showed signs of improvement in January after the flooding caused a record contraction of 10.7 percent in the fourth quarter of 2011 from the third.
"We believe the economy will grow again in the first quarter and probably expand more than 5 percent this year," Boonchai said, adding the ministry would review its growth forecast of 4.5-5.5 percent late next month.
That compares with the 5.5-6.5 percent forecast by the National Economic and Social Development Board, which compiles GDP data. The central bank has recently said economic growth could be above its forecast of 4.9 percent this year.
The central bank cut its policy interest rate in January and November to help business cope with the flooding but it has said the current rate of 3.0 percent will support growth.
Economists are split on the outcome of the next rate meeting in March; some expect another rate cut while others think the rate will be left unchanged.