Berkshire Hathaway Inc. (Berkshire) is a holding company owning subsidiaries engaged in a number of diverse business activities. Berkshire's Insurance businesses are conducted on both a primary basis and a reinsurance basis. The Company also owns and operates number of other businesses engaged in a variety of activities. On February 12, 2010, Berkshire completed its acquisition of Burlington Northern Santa Fe, LLC (BNSF), formally Burlington Northern Santa Fe Corporation. At the end of 2010, The Berkshire Hathaway Reinsurance Group (BHRG) acquired the life reinsurance business of Sun Life Assurance Company of Canada. In June 2011, Wesco Financial Corporation merged with and into a subsidiary of Berkshire Hathaway Inc. In January 2012, the Company, through its subsidiary, acquired Princeton Insurance Company (Princeton) from Medical Liability Mutual Insurance Company.