BUZZ-Amlin: best day ever for stock as MS&AD agrees to buy UK insurer for $5.3 bln

(Adds peers comparisons)

** Amlin (LSE: AML.L - news) jumps by a third after Japan's MS&AD agrees to buy UK rival for 3.5 bln pounds ($5.3 bln)

** MS&AD to pay 670p/share to buy all of Amlin, representing a 36% premium over Monday's closing price

** Stock, up 33%, by far & away top riser on both pan-European Stoxx 600 & UK's FTSE 250, in volume about half 90-day daily avg

** Fourth major international deal in as many months by Japanese insurers expanding overseas -- driven by need to diversify risk exposure geographically & secure growth beyond an ageing home market

** UK-listed peers gain on a positive knock-on effect. Lancashire jumps 7.5 pct, second-best performer on the STOXX 600, with gains coming in healthy volumes

** Peers Beazley up 4%, Hiscox (Berlin: H2X3.BE - news) 3.4% higher (RM (LSE: RM.L - news) : tricia.wright1.thomsonreuters.com@reuters.net)