The World Bank's latest projection was half that of its previous estimate of 3% in April.
The cut was "driven by relatively slow recovery of consumption and exports," said Ulrich Zachau, the World Bank's country director for Southeast Asia. "We do see a recovery, but it's slow."
High household debt and lingering economic and political uncertainty continue to weigh on private consumption, which is expected to expand 0.3% this year before it improves to 1.5% in 2015.
The Washington-based lender said exports are projected to increase by 0.7% as shipment of the country's major products--such as hard disk drives, metal and steel, petroleum products, chemical and agroproducts--fell. Exports in 2013 rose 4.2%.
Thailand is expected to expand 3.5% in 2015 as public and private investment continue to improve on the back of a more stable political situation.
Exports are likely to grow at a higher rate than this year, while the country's tourism sector is expected to perform better, the bank said.
Write to Warangkana Chomchuen at [email protected]