Berkshire Hathaway acquired about 5 million shares of UnitedHealth Group Inc. in the last quarter making a stake of about USD 1.6 billion in the company. Reportedly, the stake puts UnitedHealth at the 18th-largest position in the portfolio of Berkshire.

Shares of UnitedHealth Group are surging before the market open Friday as Warren Buffett's Berkshire Hathaway disclosed that it recently purchased shares of the beleaguered insurer. Berkshire Hathaway bought around 5 million shares of UnitedHealth last quarter,

Warren Buffett's Berkshire Hathaway has acquired 5 million shares in UnitedHealth Group , a regulatory filing showed on Thursday, sending the health insurer's stock up 7% in extended trading.