Santos Limited is engaged in exploration, development, production, transportation and marketing of hydrocarbons. During the year ended December 31, 2011, the Company�s activities included petroleum exploration, production, treatment and marketing of natural gas, crude oil, condensate, naphtha, liquid petroleum gas, and the transportation by pipeline of crude oil. It operates in four business units: Eastern Australia; Western Australia and Northern Territory (WA & NT); Asia Pacific, and Gladstone LNG (GLNG). The Asia Pacific operating segment includes operations in Indonesia, Papua New Guinea, Vietnam, India, Bangladesh and the Kyrgyz Republic. On October 28, 2011, it acquired remaining 79.1% interest of Eastern Star Gas Limited (ESG) followed by the sale of a 20% working interest in ESG�s permits to TRUenergy Holdings Pty Ltd. As of March 2, 2012, it announced that National Australia Bank Limited and its associated entities had ceased to be substantial holders in the Company.