The drug giants Pfizer and Allergan are in talks to merge.
If successful, the deal could be the largest this year. Allergan has a market value of about $113 billion.
It could also offer Pfizer something the US company has been after for a while – a way to slash its tax bill.
It could do so with a so-called tax inversion, a legal move in which a US company merges with a foreign-domiciled company to shift its address to a country with a lower tax rate.
In this case it would have Pfizer moving its tax domicile — not necessarily its management headquarters — to Ireland, where Allergan is based.
