It was the second month in a row the central bank left the interest rate charged on overnight interbank loans at its six-year high with the country’s economic growth this year expected to be closer to 5 percent, or higher than the bank’s earlier estimate of 4.5 percent.

But Bank Gov. Lee Seong-tae warned the global financial market turmoil and the slumping U.S. housing market could slow the U.S. economy, Yonhap news agency reported. That in turn could affect South Korea's growth as the United States is the country’s third-largest export market.

The interest rates were raised by a quarter of one point in both July and August to control high liquidity growth and an asset bubble, Yonhap said.

“There is ample liquidity and financial institutions' lending continues to show a steady increase," the bank said in a statement. “The volatility of financial market price variables has decreased as international financial market unrest shows some signs of easing.”