South Korean listed firms' debts soared 39 percent in 2008 from a year earlier amid cash squeeze triggered by an economic slump, the Korea Exchange (KRX) said Monday.

The total debts of 552 listed firms amounted to 118.36 trillion won (139.8 U.S. dollars) as of end-December, up 38.7 percent from a year earlier, according to a statement by the Korea Exchange.

The sharp increase was attributed to expansion in borrowing due to poor earnings amid the global economic downturn, according to KRX.

Bonds took up 49.7 percent of their total debts with the remaining portion composed of loans and other debts.