SEOUL South Korea's consumer inflation accelerated for a second month in September, outpacing market expectations, official data showed on Thursday.

The consumer price index stood 3.7% higher in September from a year earlier, after recording a 3.4% rise in August. Economists in a Reuters survey had expected the figure to stay unchanged.

It was the second consecutive month the annual rate quickened, from a 25-month low of 2.3% in July, and marked the fastest annual rise in five months.

Finance Minister Choo Kyung-ho said after the data release that inflation would likely stabilise again from October with seasonal factors easing.

On a monthly basis, the index rose 0.6%, according to Statistics Korea, compared with a 1.0% jump the previous month and a median 0.3% forecast.

Broken down by sector, prices of petroleum products jumped 4.0% over the month, agricultural prices climbed 4.1%, while public utility prices added 5.3%.

Core CPI, which excludes volatile food and energy prices, was 3.3% higher in September on an annual basis, the same as in August.

The data comes two weeks before the Bank of Korea's next policy decision. The central bank held interest rates steady for a fifth straight meeting at its last review in August, seeking to balance softer inflation and heightened risks to growth.

(Reporting by Jihoon Lee; Editing by Ed Davies and Tom Hogue)