SK Group is one of the largest conglomerates in South Korea. SK Group is composed of 95 subsidiary and affiliate companies that share the SK brand and culture named SKMS. Its businesses are primarily involved in the chemical, petroleum, and energy industries. It also owns South Korea's largest wireless mobile phone service provider, SK Telecom, and provides services in construction, shipping, marketing, local telephone, high-speed Internet, and wireless broadband. SK Group is composed of 95 subsidiary and affiliate companies that share the SK brand and culture named SKMS (SK Management System).