Economic growth in most major Southeast Asian nations either slowed or remained at the same levels in the second quarter this year.

Thailand's GDP grew 1.8 percent in the April-to-June quarter, compared with the same period last year. Though the GDP remained in positive territory, the growth rate has shrunk from the previous quarter.

The country's manufacturing sector has been in a slump as exports of vehicles and precision instruments to China, the US and Europe remain at low levels.

The Indonesian economy, which is the largest in the region, showed growth of 5.2 percent from the January-to-March quarter.

Likewise, the Philippines marked growth of 4.3 percent, Malaysia 2.9 percent, and Singapore, 0.5 percent. The pace of increase eased or remained at similar levels from the previous quarter.

Against this backdrop, the Thai and Singapore governments revised downward their annual growth projections for this year.

As the slump of real estate market is lengthening in China, concern over an economic slowdown in Southeast Asia is growing stronger due to the region's close economic ties with China.