Thailand's economy is expected to grow 2.5% to 3.0% this year, unchanged from a previous forecast, a leading joint business group said on Wednesday.

The economy is expected to grow 2.8% to 3.3% next year, said the Joint Standing Committee on Commerce, Industry and Banking, which includes representatives from those sectors.

Southeast Asia's second-largest economy grew 1.5% in the July-September quarter from a year earlier, the slowest this year, due to declining exports and government spending. (Reporting by Kitiphong Thaichareon, Chayut Setboonsarng and Satawasin Staporncharnchai)