SHANGHAI, June 27 (Reuters) - China's yuan slumped to its weakest level against the dollar since December 2010 on Monday as deep uncertainty buffeted global markets after Britain's vote to leave the European Union last week, traders said.

The yuan hit an intraday low of 6.6402 per dollar in early trade, down 0.2 percent from Friday's close, also tracking the central bank's midpoint, which was fixed at 6.6375 on Monday - the lowest official guidance rate since December 2010.

The dollar index .DXY jumped nearly 1 percent in early Asian trade on Monday as the British pound GBP= remained under siege, sliding back toward a 31-year low as sentiment towards the currency remained in tatters after Brexit. urn:newsml:reuters.com:*:nL4N19I0OS

(Reporting by Lu Jianxin and Nathaniel Taplin; Editing by Shri Navaratnam) ((jianxin.lu@thomsonreuters.com; 86 21 6104 1792; Reuters Messaging: jianxin.lu.thomsonreuters.com@reuters.net))