South Korea's top 100 listed companies have seen their average operating margin lose steam over the past three years amid a slowdown in overall business conditions, a market tracker said Monday.

The average operating margin of the leading firms stood at 5.48 percent for the 2014-2016 period, lower than the comparable figure of 5.8 percent from 2007-16, according to Chaebul.com.

The figure refers to the ratio of operating income to sales and serves as a key barometer of a company's profitability.

Of the total, 63 companies, including top-cap Samsung Electronics Co., saw their three-year median hover below the average for the past decade, with seven out of the top 10 companies suffering setbacks.

Samsung, the world's top smartphone and memory chipmaker, posted an operating margin of 10.07 percent for the last three years, down from the 10-year average of 10.27 percent.
 

The three-year operating margin of Hyundai Motor Co., stung by the fallout from a diplomatic row between South Korea and China over the deployment of a US missile defense shield here, came to 8.28 percent, compared with 8.39 percent for the 10-year period.

In particular, home appliance giant LG Electronics Inc. and shipbuilding giant Hyundai Heavy Industries Co. chalked up negative operating margins for the past three years as they swung to a loss.

Chip giant SK hynix Inc., bolstered by a recent boom in the semiconductor business, registered an operating margin of 25.07 percent for the past three years, compared with 10.98 percent over the last decade. SK hynix posted the best improvement over the cited period.

KT&G Corp., South Korea's leading tobacco producer, had the highest operating margin of 42.16 percent for the past three years.

The market tracker said shipbuilders, securities companies, communications firms and steelmakers have seen their profitability worsen in recent years.

Annual sales of the 100 companies averaged 1,058 trillion won ($930 billion) over the past three years, higher than the comparable figure of 945 trillion won for the 10-year period. Their average operating profit came to 57.9 trillion won during the three-year period, compared with the 10-year median of 54.8 trillion won. (Yonhap)