South Korea’s SK Group announced a reshuffling of its top management at a board meeting today.

The company said it has replaced the heads of four of its subsidiaries — SK Telecom, SK Innovation, SK Networks and SK C&C. The group has 95 subsidiary and affiliate companies and eight within the telecoms and semiconductor sectors.

SK Planet chief operating officer Jang Dong-hyun (pictured) was named president and CEO of SK Telecom, the country’s largest mobile operator, replacing Ha Sung-min who has been CEO since early 2011 (he was hired by the operator in 1996).

Jang, who joined SK Telecom in 2000 after spending eight years at Yukong (now SK Innovation) and a year a SK Group, took the COO position at SK Planet, the company’s services platform subsidiary, last January. He also served as head of the strategic planning division as well as head of marketing.

Jeong Cheol-jin was appointed president at SK Innovation, Moon Jong-hoon was promoted as president of SK Networks, and Park Jung-ho, a VP at SK C&C, takes the top position at the firm.

SK Telecom is the market leader with a 49 per cent share. More than 60 per cent of its 27 million mobile connections are 4G, according to GSMA Intelligence. Rival LG Uplus has 79 per cent of its connections using 4G technology, and KT has 64 per cent, demonstrating the country’s leadership in this area.

The country’s three major mobile players continue to battle for new 4G customers, offering attractive subsidies despite new government regulations that limit them to about $280. All three were each fined KRW800 million ($717,000) last week for not reducing their subsidy levels to comply with a new rules.