UK's Treatt jumps on Exponent's buyout proposal at premium
** Shares of Treatt Plc TET.L up 21% at 272p, highest since June 20 ** Food ingredients maker gets proposal from PE firm Exponent to be bought out for 260p a share ** Proposal at a premium of 16% to TET's last close, values Treatt at 156.6 mln pounds ($211.6 mln) ** Up to last close, stock had fallen nearly 54% so far this year($1 = 0.7400 pounds) (Reporting by Prerna Bedi in Bengaluru) ((Prerna.Bedi@thomsonreuters.com; +91 98052 24616;))