Fears spread among South Koreans over their economy's heavy dependence on top two conglomerates after a local corporate data provider warned it.

On Jan. 13, CEO Score, an online corporate productivity evaluation site, announced a report that the ratio of combined revenues of Samsung Group and Hyundai Motor Group to GDP reached 35 percent in 2012, up from 23.1 percent in 2008.

The report terrified people as underperformance of the top two chaebols could result in overall economic slump, alerting policymakers to the need for a separate assessment of the economy after excluding business activities of the top two from total economic performance. Finance Minister Hyun Oh-seok admitted the need, saying that the ministry was appreciating economic concentration of Samsung and Hyundai.

Revenue of Samsung Electronics, the country's No. 1 company and a flagship unit of Samsung Group, equaled to 16.2 percent of GDP in 2012, according to the CEO Score. It was the highest among the world's top 20 economies in terms of GDP. The figures for the United States, China, Japan, Germany and France were far below 10 percent.

"Samsung and Hyundai's dominance will last over the next 10 more years," Park Ju-Geun, president of CEO Score, said in an interview with Xinhua Friday, at his office in Seoul filled with books on economics, politics, finance and statistics.

Park said it will take around 10 years to enhance economic constitution of South Korea, which has been bred by manufacturing exporters like Japan. Among global top 20 companies selected by the U.S. magazine Fortune, only manufacturers were Samsung Electronics of South Korea and Toyota Motor of Japan.

"It's true the economy depends on a couple of companies. It indicates the need for portfolio diversification from cars and smartphones to finance, pharmaceutical and energy sectors, not oppressing the current leading players," said Park.