A total of 159 South Korean companies suffered downgrades in their credit ratings in 2015, according to government data.

The number was the largest since the 1997-1998 Asian financial crisis when 171 firms had their ratings slashed, said the Financial Supervisory Service on Wednesday.

During the same period, 26 companies saw their credit ratings rise. The financial regulator said this marked the smallest increase since 1998.

The FSS data also showed that credit downgrades were most witnessed in sectors such as construction, refinery, petrochemicals and steelmaking, which have been experiencing global and nationwide sluggish growth.