The business sector is cutting key economic indicators for the fourth time this year as negative factors persist.
Vallop Vitanakorn, vice-chairman of the Federation of Thai Industries (FTI), said the weak recovery of major trade partners such as the US and the EU and the economic slowdown in China could cut Thai exports by more than 2% this year.
Exports account for 70% of Thailand's GDP.
In its latest revision of early July, the FTI on behalf of the Joint Standing Committee on Commerce, Industry and Banking (JSCCIB) forecast exports to contract by 2% this year, down from growth of 1%.
The JSCCIB also cut its Thai GDP growth forecast to 3% from 3.5%.
"The latest export figure fell by more than we expected," Mr Vallop said. "We are about to revise the export figure again, which could be lower than our latest forecast."
He said the FTI would release its revised forecast this Monday, when the JSCCIB holds its monthly meeting.
The Commerce Ministry reported June exports fell by 7.87% year-on-year to US$18 billion, while first-half exports fell by 4.84% to $106.8 billion.
The FTI is concerned that exports in the second half will worsen, citing few signs of increasing demand — especially from China, the top importer of Thai goods.
The weak economic outlook in major importing countries could force buyers to hold back orders during the peak season in the fourth quarter, when people celebrate Christmas and the New Year.
"Normally buy orders are placed three months in advance, but with everything quiet now, orders in the last quarter are likely not to be that good," Mr Vallop said.