BANGKOK (Reuters) - Thailand's economy expanded 0.3 per cent in January-March from the prior three months, contrary to expectations for a contraction, but the latest data still indicates the growth outlook remains weak.

The national planning agency said on Monday that on an annual basis, growth in the first quarter was 3.0 per cent, lower than the a Reuters poll projection of 3.4 per cent.

The poll's median for quarterly change was a shrinkage of 0.5 per cent from October-December, which saw a revised expansion of 1.1 per cent.

Since the army seized power a year ago to end political unrest, the military government has been unable to revive Southeast Asia's second-biggest economy. Exports have fallen and domestic demand have remained sluggish.

Also on Monday, the government's figure for growth last year was revised to 0.9 per cent, from 0.7 per cent reported earlier.

The National Economic and Social Development Board (NESDB), which compiles GDP data, revised seasonally adjusted quarter-on-quarter growth for October-December to 1.1 per cent from 1.7 per cent stated earlier. On-year growth for the last quarter of 2014 was revised to 2.1 per cent from 2.3 per cent.