The Bank of Korea, in a survey of 1,723 companies, said last year's corporate profitability -- the ratio of operating profit to sales -- fell to 4.8 percent from 5.3 percent in 2011 as the global conditions affected sales growth.
The South Korean economy, which is heavily dependent on exports, is Asia's fourth largest after China, Japan and India
The bank's survey said 2012 sales grew 5 percent on-year in 2012, down from 14.4 percent growth in 2011.
"Despite low rates, local firms refrained from borrowing as it was difficult for them to generate profits or increase investment amid the slowing economy," said Kim Kyung-hak, the bank's head of the corporate statistics team, Yonhap News reported.
The corporate performance reflected the country's slow economic growth of 2 percent in 2012. The bank's growth outlook for 2013 is 2.6 percent, while that of the government is 2.3 percent.
The bank said the slowing corporate profitability curtailed companies' capacity to cover financial costs.