AstraZeneca shares plunge over talks with US cancer drug firm on $400bn merger

Bristol Myers Squibb tie-up would create world’s fourth largest drugmaker but analysts question rationale for deal More than £15bn was wiped off the value of Britain’s biggest drugmaker, AstraZeneca, on Monday after a report that it was in discussions to take over its US rival Bristol Myers Squibb in a deal that would create a near $400bn (£300bn) pharmaceutical group. AstraZeneca, run by Pascal Soriot, its longtime chief executive, is the second biggest listed company in the UK, with a market…