Korea Exchange Bank saw its network system, including Internet banking and automated teller machines, break down for about 1-1/2 hours late Thursday.

Though KEB said it restored the services around 8 p.m., the commercial bank did not reveal the factors for the breakdown.

The Financial Supervisory Service plans to launch an inquiry into the bank for its network glitch early Friday.

KEB, controlled by U.S. Lone Star Funds for more than eight years, has recently been acquired by Hana Financial Group.

By Kim Yon-se (kys@heraldcorp.com)