The number of South Korean companies affiliated with large business groups under tight supervision rose by 52 in the August-October period as conglomerates expanded new businesses, the antitrust regulator said Wednesday.

The total number of affiliates on the Korea Fair Trade Commission's (KFTC) watch list reached 2,704, as of end-October, compared with 2,652 three months earlier, according to the commission.

Major business groups newly launched or acquired 106 units, while offloading 54 others from affiliate lists in the three-month period.

The rise came as a larger number of big companies made forays into new business fields and overhauled their business portfolios to strengthen their competitive edges, according to the regulator.

South Korean internet giant Kakao Corp. newly added the largest number of affiliates under its wing with 14, followed by energy-to-telecom giant SK Group with 10 units.

The country's largest family-run conglomerate Samsung Group held 59 affiliates under its wing as of Monday. Automaking giant Hyundai Motor Group had 56 affiliates, and SK Group held 165 units.

Under fair trade law, affiliates of large conglomerates with assets exceeding 10 trillion won ($8.5 billion) are restricted from making equity investments in their affiliated companies or offering loan guarantees to each other.

The conglomerates are also required to make public filings on their non-listed affiliates and are barred from engaging in excessive trading among affiliates. (Yonhap)