SK Group has more than 70,000 employees who work from 113 offices worldwide. While its largest businesses are primarily involved in the chemical, petroleum, and energy industries, SK Group 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 (WiBro). On March 20, 2010, SK further broadened its range of business to semiconductors by merging Hynix into SK Hynix, the world's second largest memory semiconductor manufacturer.