PSO was formed in 1976 through the merger of Premier Oil Company Limited and State Oil Company Limited. It underwent corporate renewal from 2004-present to improve organizational structure, empower employees, and increase transparency. PSO is Pakistan's leading oil company, with the largest retail network and storage capacity. It fuels many sectors of the economy and plans to expand into new markets and reduce costs through vertical integration. PSO's vision is to be an innovative and dynamic energy company that excels in customer service, and its mission is leadership in energy markets through high quality petroleum products and services based on values like excellence, teamwork, integrity, innovation, and corporate responsibility.