The ratio of operating profit to sales of firms in the country reached 7.4 percent in the second quarter, up from 5.2 percent tallied a year ago, according to the data from the Bank of Korea (BOK).
At the same time, the pretax net profit margin of South Korean companies rose on-year to 8.2 percent from 4.6 percent.
Their sales jumped 18.7 percent on-year in the second quarter, compared with growth of 7.4 percent a year ago.
By sector, manufacturing firms posted a 24.3 percent on-year jump in second-quarter sales, with their ratio of operating profit to sales widening to 9 percent.
Non-manufacturers' sales also rose 12.4 percent on-year in the second quarter, with their operating profit margin gaining 5.4 percent.
The financial health of local companies slightly improved in the second quarter, with their debt to equity ratio falling to 86.6 percent from 89.9 percent. (Yonhap)