The ratio of bad loans at South Korean banks rose in 2013 as the massive amount of loans extended to local shippers and builders turned sour amid the economic slump, the financial watchdog said Friday. The ratio of non-performing loans held by 18 local banks came to 1.77 percent as of the end of December last year, up 0.44 percentage point from the 1.33 percent tallied at the end of 2012, according to the Financial Supervisory Service (FSS).