Business sentiment among South Korean manufacturers remained flat in December after performances worsened for some industries despite a recovery in semiconductor-related companies.

According to the Bank of Korea on Thursday, the business survey index(BSI) for manufacturers posted 70 in December, unchanged from the previous month, showing that pessimists outnumber optimists with a reading below 100.

The figure had previously posted growth for three consecutive months from August.

The central bank attributed the flat figure to poor performance by chemical products and metal works industries which came amid improved performances by semiconductor-related industries.

The BSI for non-manufacturers, which includes restaurants, wholesalers and retail businesses, climbed one point to 70.

Meanwhile, local firms' business outlook for January marked 68, down one point from the previous month.