South Korea's economic growth rate for 2015 is expected to slow to 2.4 percent from an earlier estimate of 2.7 percent due to weak consumer spending and falling exports, a private think tank said Tuesday.

In its latest economic outlook, the Korea Economic Research Institute predicted Asia's fourth-largest economy will likely expand 2.6 percent in 2016 from this year.

KERI's projection is far lower that the government's revised growth forecast of 3.1 percent for this year.

Affiliated with the country's top business lobby, the Federation of Korean Industries, the think tank blamed the growth downgrade on a continued slump in South Korea's domestic demand and worsening export conditions, including China's cooling economy and its currency devaluation.

China is the largest export market for South Korea, which relies heavily on overseas shipments for its economic growth.

"China's economic slump will likely have a bigger impact on the South Korean economy than a U.S. interest rate hike," the think tank said. "There is a possibility of additional currency devaluation in China."

KERI expected South Korea's consumer prices to rise 0.8 percent on-year in 2015, with the consumer inflation rate rising to 1.8 percent in the coming year.

South Korea's current account surplus is expected to reach $105.4 billion this year and $102.2 billion in 2016, respectively, according to KERI. (Yonhap)