BUZZ-Shire: shares slump, proposed $30 bln all-stock deal with Baxalta
** Shire (Xetra: S7E.DE - news) slides nearly 8 pct after co confirms it made a proposal to merge with Baxalta (Berlin: 9BX.BE - news) in an all-stock deal
** Baxalta shares spike 28.2 pct in the US premarket
** Shire says Baxalta has declined to engage in discussions
** Shire shares poised for worst drop since a deal with AbbVie (Xetra: 4AB.DE - news) was called off last October
** One trader says news likely to dent speculation about Shire getting taken over
** Shire has been an active dealmaker this year with the latest coming a day ago with a $300 mln purchase of U.S.-based Foresight Biotherapeutics
(RM (LSE: RM.L - news) : sudip.kargupta.thomsonreuters.com@reuters.net; RM: alasdair.pal.thomsonreuters.com@reuters.net)