SEOUL, June 10 (Xinhua) -- South Korea's corporate revenue grew more slowly last year due to the sluggish performance of the oil refining and construction industries, central bank data showed Wednesday.

Revenue for 13,918 manufacturers and 20,538 non-manufacturers subject to external audit, excluding financial firms, rose 2.5 percent in 2025 from a year earlier after expanding 4.2 percent in the previous year, according to the Bank of Korea (BOK).

Sales by manufacturers swelled 3.2 percent last year, slower than an increase of 5.2 percent in the prior year.

Revenue for non-manufacturers gained 1.6 percent in 2025 after going up 3.0 percent in 2024.

Revenue among construction companies declined 9.6 percent last year, while those in the oil refining, chemical and electrical equipment sectors reduced in single digits.

Corporate profitability improved. The ratio of operating profit to revenue advanced to 6.2 percent in 2025 from 5.4 percent in the previous year.

The ratio for manufacturers climbed from 5.5 percent to 6.9 percent in the cited period amid higher semiconductor price, while the reading for non-manufacturers mounted from 5.2 percent to 5.4 percent.

The interest coverage ratio, which measures a company's ability to pay interest expenses with operating profit, came to 369.8 percent in 2025, up from 305.8 percent in the previous year.

The debt-to-equity ratio for local companies stood at 98.3 percent last year, down from 103.4 percent a year earlier.