The combined net profit of six credit bureau firms in South Korea jumped 31 percent on-year in 2016, as they expanded their business portfolio into new sectors, the nation's financial regulator said Tuesday.

The combined net income of the six credit bureau firms, which collects and evaluates credit data between consumers and financial firms, stood at 57.2 billion won ($51.3 million) last year, up 13.6 billion won from 2015, the Financial Supervisory Service (FSS) said in a statement. 

Their combined operating profit rose 5.9 percent on year to 493 billion won in 2016.

The six firms include Korea Credit Bureau, NICE Investors Service and Korea Ratings.

Meanwhile, the combined net profit of 22 debt-collection service firms in South Korea gained 2.2 percent on year to 23.4 billion won, according to the FSS.

Their combined operating profit fell 0.2 percent on year to 715.2 billion won last year, hit by a fierce competition and a decline in commission fees, it said. (Yonhap)