Major listed companies belonging to South Korea's top 10 conglomerates saw their operating profits inch down in 2011 from a year earlier on global economic woes, data showed Thursday. The combined operating profit of the 73 companies reached 73.89 trillion won (US$64.7 billion) last year, down 1.04% from the previous year, according to the Korea Exchange, the nation's bourse operator. Of the conglomerates, only four posted gains in operating profits with the remainder suffering declines. SK Group, South Korea's third-largest conglomerate, posted an operating profit of 14.48 trillion won in 2011, up 36% from the year earlier and the biggest leap among the 10 conglomerates, South Korea's (Yonhap) news agency reported. Hyundai Motor Group, the world's fifth-largest carmaker, earned 17.61 trillion won in 2011 operating profit, up 29.11% from a year earlier, thanks to strong performances by its flagship companies, Hyundai Motor Co. and Kia Motors Corp. However, South Korea's largest conglomerate Samsung Group saw its operating profit decline 9.84% on-year to reach 20.61 trillion won in 2011, affected by the overall slump in the information technology industry. Samsung has global tech giant Samsung Electronics Co. under its wing. Hanjin Group, which controls South Korea's top container line Hanjin Shipping Co., posted the worst performance, with its operating profit tumbling to around 30 billion won from slightly over 2 trillion won. The plunge in Hanjin Group's operating profit was caused by the deepening downturn of the global shipping industry stemming from the eurozone debt crisis, according to the data.