Local companies issued 17.69 trillion won (15.8 billion U.S. dollars) worth of bonds in October, up 30.3 percent from the previous month, according to the Financial Supervisory Service (FSS).
It came as the country's central bank left the benchmark interest rate unchanged at 1.50 percent for the past year. The bank raised it to the current level in November last year from an all-time low of 1.25 percent.
Bond sales by industrial companies tumbled 35.2 percent, but bonds issued by financial firms surged 47.8 percent. Asset-backed securities (ABS) issuance more than quadrupled last month.
Meanwhile, initial public offering (IPO) by local companies plunged 62.5 percent in October from a month earlier as the local stock market lost ground on worry about trade conflict among major economies.