Lotte Group was the top spender for mergers and acquisitions among the country’s business groups over the past six years, industry data showed Sunday.

South Korea’s fifth-largest conglomerate has signed 21 buyout deals worth some 7.6 trillion won ($6.6 billion) since January 2010, according to the data by corporate researcher CEO Score.

The amount accounts for 20.2 percent of the 37.78 trillion won for 239 acquisition deals signed by the nation’s top 30 firms.

Lotte’s decision to take over Samsung SDI’s chemical business and Samsung Fine Chemicals for around 3 trillion won in October was the latest in a frenzy of mega deals signed by the firm.

Since Lotte Group chairman Shin Dong-bin took the helm in 2011, the conglomerate has aggressively expanded its sprawling business empire with a number of takeover deals, including the nation’s top home appliance retailer Hi-Mart for 1.2 trillion won in 2012.

This year, Shin also led several acquisitions such as KT Rental and New York Palace Hotel, for 947 billion won and 505 billion won, respectively.

“Lotte has been sealing bold M&A deals while not losing focus on its core businesses, such as food and beverage, retail and chemical sectors,” an industry watcher said.

Buoyed by the buyout deals, Lotte’s assets jumped to 117.3 trillion won as of October, up 35 percent from 87.2 trillion won in 2010, the data showed.

Hyundai Motor Group and SK Group were the second- and third-largest spenders for M&As.

Hyundai Motor, the world’s fifth-largest automotive group, has acquired only three companies, but splashed 5.49 trillion won for high-profile deals including Hyundai Engineering & Construction.

It is the largest M&A transaction in the country since 2010, followed by the 3.37-trillion won deal between SK Group and Hynix in 2012.

SK invested a total of 4.4 trillion won in 18 M&A deals ― including the Hynix deal and a recent takeover plan for the country’s top cable TV provider, CJ Hello Vision.

In terms of the number of deals reached, CJ was the most active in striking acquisition deals, purchasing 36 firms including logistics company Korea Express and On Media. Though the firm took sixth place in terms of amount spent, with deals worth just 2.8 trillion won.

By Park Han-na (hnpark@heraldcorp.com)