UK's Spectris ditches KKR in favour of Advent's sweetened $6.4 billion offer

Aug 1 (Reuters) - British scientific instruments maker Spectris has agreed to private equity firm Advent's sweetened takeover offer worth 4.8 billion pounds ($6.38 billion), including debt, as the battle for Britain's biggest takeover target of the year heats up.

Shares in the London-headquartered company closed up 2.2% at 4,078 pence, a near four-year high. They have more than doubled in value since Advent made its first buyout proposal on June 9.

Advent is now offering Spectris shareholders 40.72 pounds per share in cash and an interim dividend of 28 pence, topping a 4.7 billion pound offer from U.S. investment firm KKR KKR.N, which also included debt.

KKR is evaluating its next steps and will update the market when appropriate, it said in a statement after Spectris' board withdrew support for its offer.

The U.S. firm also recently lost out on British healthcare real estate investor Assura AGRP.L, which recommended a rival bid from Primary Health Properties PHP.L.

Britain’s subdued valuations and relative stability have attracted overseas buyers, with a flurry of bids in recent months highlighting the appetite for UK assets.

Spectris provides hardware and software to sectors including pharmaceuticals, steel and automotive.

($1 = 0.7528 pounds)