The number of South Korean companies affiliated with large business groups under tight supervision rose by 34 in the three months ending Jan. 31 as conglomerates expanded new businesses, the antitrust regulator said Thursday.

The total number of affiliates on the Fair Trade Commission (FTC) watch list reached 2,738 as of end-January, compared with 2,704 three months earlier, according to the commission.

Major business groups newly launched or acquired 112 units, while offloading 78 others from affiliate lists in the November-January period.

More firms established or bought entities in line with their environmental, social and governance (ESG) management, and added affiliates to overhaul their business portfolios, according to the regulator.

Energy-to-telecom giant SK Group newly added the largest number of affiliates under its wing with 16, followed by Kakao Corp., the operator of the country's most-used mobile messenger KakaoTalk, with 12 units.

South Korea's largest family-run conglomerate Samsung Group held 60 affiliates as of Thursday. Automaking giant Hyundai Motor Group had 57 affiliates, and SK Group held 176 units.

Under fair trade law, affiliates of conglomerates with assets exceeding 10 trillion won ($8.3 billion) are restricted from making equity investments in their affiliated companies or offering loan guarantees to each other.

Large business groups with assets of 5 trillion won or more are also required to publicly file details on inter-affiliate transactions, their ownership structure and key information on non-affiliates. (Yonhap)