Samsung Electronics Co., the world's top smartphone maker, and two other South Korean companies accounted for nearly a third of combined net profits of local firms last year, data showed Monday, in the latest sign of concentration of wealth in a few conglomerates in Asia's fourth-largest economy.

The other two companies are Hyundai Motor Co. and its smaller sister company Kia Motors Corp., the two major flagship units of Hyundai Motor Group, the world's fifth-largest carmaker.

The combined net profits of Samsung, Hyundai and Kia came to 24.8 trillion won ($23.3 billion) in 2012, accounting for 28.6 percent of 86.6 trillion won generated by 464,425 local companies, according to the data of the Bank of Korea and financial information provider FnGuide.

Samsung Electronics is a flagship unit of Samsung Group, South Korea's largest family-controlled conglomerate.

In 2009, the combined net profit of Samsung, Hyundai and Kia accounted for 14 percent of total profits of the South Korean companies. The ratio of the three companies' combined net profit increased to 16.2 percent in 2010 and to 18.9 percent in 2011, according to the data.

The latest performance of Samsung, Hyundai and Kia suggests that their dominance in net profits of South Korean companies could continue this year.

Last week, Samsung Electronics posted a net profit of 8.24 trillion won in the July-September period, compared with a profit of 6.56 trillion won a year earlier.

Meanwhile, Hyundai Motor said its third-quarter net profit edged up 3.9 percent on-year to 2.25 trillion won. Kia posted a net profit of 903.2 billion won in the July-September period, up 8.9 percent from a year earlier.

Kim Sang-jo, an economics professor at Hansung University, said the government should change its economic policy which he says is dependent on the so-called trickle-down effect from a few conglomerates. (Yonhap News)