Halliburton is an American multinational corporation. One of the world's largest oil field service companies, it has operations in more than 70 countries. It owns hundreds of subsidiaries, affiliates, branches, brands, and divisions worldwide and employs approximately 50,000 people. The company has dual headquarters located in Houston and in Dubai, where Chairman and CEO David Lesar works and resides. The company remains incorporated in the United States. Halliburton's major business segment is the Energy Services Group (ESG). ESG provides technical products and services for petroleum and natural gas exploration and production. Halliburton's former subsidiary, KBR, is a major construction company of refineries, oil fields, pipelines, and chemical plants. Halliburton announced on April 5, 2007 that it had sold the division and severed its corporate relationship with KBR, which had been its contracting, engineering and construction unit as a part of the company. The company has been involved in numerous controversies, including the Deepwater Horizon explosion, for which it agreed to settle outstanding legal claims against it by paying litigants $1.1 billion.