Only eight of South Korea's conglomerates have ranked on the list of 50 companies with the highest sales consecutively for the past 35 years, with 70 percent either being eliminated or undergoing a change in ownership.

According to the privately-run Sustainable Growth Institute on Tuesday, the combined sales of the top 50 companies totaled three-point-four trillion won in 1984, compared to 872 trillion won in 2018.

Companies had to record sales surpassing 200 billion won to be on the list in 1984, but now they have to post sales exceeding four trillion won.

Only eight conglomerates including Samsung C&T, Hyundai Engineering & Construction, Samsung Electronics and Hyundai Motor have remained on the list for the past 35 years.

Seventy percent of conglomerates, including Daewoo Group and Dongah Construction Industrial, were either eliminated or went through ownership changes, many during the Asian financial crisis in the late 1990s.