Shell Canada Limited () is the principal Canadian subsidiary of British energy major Shell plc and one of Canada's largest integrated oil companies. Exploration and production of oil, natural gas and sulphur is a major part of its business, as well as the marketing of gasoline and related products through the company's approximately 1,800 stations across Canada. After a global reorganization by the European parent, Shell's North American operations are controlled by Shell Energy North America, which is headquartered in Houston, Texas. Shell Energy North America's Canadian operational unit, Shell Canada, maintains a regional corporate office in Calgary, Alberta. Shell Canada also maintains a major office in Toronto, Ontario. History Shell Canada's shares were originally independently traded on the Toronto Stock Exchange. The company was 78% owned by Royal Dutch Shell which in 2006 launched an $8.7-billion takeover of the 22% of Shell Canada that it didn't own. In March 2007 the shareholders of Shell Canada Ltd. accepted a $45.00 per share cash offer from Royal Dutch Shell Plc. This acquisition was primarily driven by the desire of the parent company to take total control of its Canadian division's unconventional resources, specifically the oil sands. The move was unanimously approved by the independent members of the board of directors. In 2003, Royal Dutch Shell had appointed a British executive, and former Chairman of Shell in the UK, Clive Mather, as president and CEO of Shell Canada. As a consequence of the stock acquisition by Royal Dutch Shell, all Shell Canada executives holding stock options benefitted. Shell Canada announced on Mr Mather's retirement from the company shortly after the acquisition was completed that his total pay package for his final year (2007-07) was $4.9-million Including bonuses, stock options and pension contributions and that on leaving the company, Mr. Mather was additionally eligible for a lump sum payment equal to his annual gross salary. His total benefit in that year was, therefore $9.8 million of which some $5 million was from exercised stock options, making him one of the highest remunerated employees in Royal Dutch Shell. In 2006, Shell Canada acquired the oil sands developer BlackRock Ventures Inc. for C$2.4 billion. As a part of this deal, Shell acquired the Orion oil-sands project near Cold Lake, Alberta. In May 2012, Shell announced that it has put the project up for sale. In 2007, the company invested $20 million (CAD) into an expansion