Astrazeneca explores $400bn megadeal with US rival

Astrazeneca is exploring a $400bn (£300bn) merger with US rival Bristol Myers Squibb, in a deal that would create one of the world’s largest pharmaceutical groups. The FTSE 100 giant has held talks with the US group in recent months about a possible tie-up, according to reports in the Financial Times.  Talks could lead to a…