Shire, the giant pharmaceutical company that relocated its head office from the UK to Ireland for tax reasons a number of years ago has surprised investors by launching a $30bn hostile bid to acquire the American company, Baxalta, which is also involved in the manufacture of drugs to combat rare diseases.

If the all-share deal proves successful, the combined business would double global revenues to $12bn, while Baxalta shareholders would own just under 40 percent of the new group.

Analysts say the merger, which Baxalta management has already declined, would also protect Shire itself from takeover approaches; it was subject to an approach from Abbvie last year, attracted by the low corporate tax base in Ireland, but the deal was abandoned when the US tax authorities tightened their rules on so called 'tax inversion' deals.

The Irish Times reports this morning that Cortendo, a Swedish/American biopharmaceutical company has informed its shareholders that it has informed the Central Bank here of its plans to relocate its corporate headquarters to make its operations more tax efficient.