Amid rising criticism of commercial loan firms over their exorbitant interest rates and frequent trouble with clients, the Financial Supervisory Agency said Wednesday the three leaders in the industry have charged an average of 20.87 percent in interest on loans, or about nine times the rate they pay to borrow funds.

Sources said, however, that the collateral-free guaranteed loan lenders, which target small and midsize businesses, often charge 30-plus percent on loans.

The agency said at a Lower House Finance Committee session that it estimates that Nichiei Co., Shohkoh Fund & Co. and Shinki Co. borrow at 2.33 percent.