SK Inc, formerly SK Holdings Co Ltd, is a Korea-based company principally engaged in the petroleum business. The Company engaged in the petroleum businesses, mobile communication services, energy and information technology distribution and construction businesses through subsidiaries including SK Innovation Co Ltd, SK Telecom Co Ltd, SK Networks Co Ltd, SK Engineering & Construction Co Ltd, SK E&S Co Ltd and others. SK Innovation Co Ltd is a holding company operates businesses related to petroleum and chemistry. SK Telecom Co Ltd provides mobile communication services of voice and data. SK Networks Co Ltd is engaged in the businesses of energy and information technology distribution as well as car rental. SK Engineering & Construction Co Ltd engages in the businesses of infrastructure, building and residence as well as plant construction. SK E&S Co Ltd is mainly engaged in the gas company and combined cycle power generation business.