From left, former Leeum Museum of Art Director Hong Ra-hee, Hotel Shilla President Lee Boo-jin and Samsung C&T President Lee Seo-hyun / Yonhap

Chaebol families unloaded over 5 trillion won ($3.62 billion) worth of shares over the last year and a half, including 3.31 trillion won from the mother and two younger sisters of Samsung Electronics Executive Chairman Lee Jae-yong, data showed Wednesday.

The data released by corporate tracker CEO Score showed spouses, children and other members from founding families of 71 conglomerates sold stocks worth 5.067 trillion won in total between January 2023 and June this year.

The stocks were issued by corresponding affiliates of the 71 conglomerates.

CEO Score assessed that Chaebol families sold shares to secure cash for inheritance taxes, succession planning and other purposes essential for the longevity of their conglomerates.

The Samsung family spearheaded the sales, with the executive chairman's mother, Hong Ra-hee, and his two sisters, Lee Boo-jin and Lee Seo-hyun, occupying the top three positions.

A former director of the Leeum Museum of Art, Hong unloaded shares worth 1.405 trillion won in Samsung Electronics.

Lee Boo-jin, president of Hotel Shilla, and Lee Seo-hyun, president of Samsung C&T's fashion division, each secured 615.9 billion won and 760.6 billion won in cash by selling shares in Samsung Electronics, Samsung C&T and Samsung SDS, among others.

The shares sold by the three totaled 3.31 trillion won.

The mother and the daughters have been selling Samsung shares for years to pay off inheritance tax after the death of the late Samsung Electronics Chairman Lee Kun-hee in October 2020.

He was the richest man in Korea at the time of his death, with a fortune worth an estimated 26 trillion won. The Lee family was hit with more than 12 trillion won in inheritance tax, as Korea has a top inheritance tax rate of 50 percent.

Of other family members of the 71 conglomerates, Hyundai Department Store Chairman Chung Ji-Sun sold the company's shares worth 180.9 billion won as the firm transitioned to a holding company.