Samil PricewaterhouseCoopers was the strongest of them, having 295 corporate customers (15.5 percent). Samjong KPMG was next with

234 (12.5 percent), followed by Deloitte Anjin with 221 (11.6 percent). Ernst & Young Hanyoung had 200 clients (10.5 percent).

Samil had the biggest staff, with 1,923 employees. Its clients include South Korea's richest company, Samsung Electronics, and the largest portal site, Naver. The second-largest market cap firm, SK hynix; Hyundai Mobis; and Korea Electric Power Corp. are overseen by Samjong.

Anjin's customers include Hyundai Motor, SK Innovation and Kia Motors. Hanyoung handles Lotte Chemical and Hana Financial Group, among others.

Such a clean sweep by the top firms left others with a dearth of big businesses. Of the 108 accounting firms, 18 had only one listed company as a client. Another 20 had two such customers.

There were 164 accounting firms in the country as of the end of January this year. Given the latest breakdown of customers, this suggests that about 34 percent of them have no corporate clients.

Regulators don't see immediate remedies in such skews. Anjin earlier this month was barred from taking on new audits for one year as a punishment for its failure to discover and report exponential business losses at Daewoo Shipbuilding & Marine Engineering. The suspension will affect some 200 listed companies signed on as its clients, but regulators expect that a majority of these clients will move to other big name accounting firms. (Yonhap)