UPDATE 1-Pfizer set to buy Allergan for more than $150 bln-sources
November 22, 2015 at 14:52 PM EST
Nov 22 (Reuters) - Pfizer Inc was due to secure formal board approval on Sunday for its acquisition of Botox maker Allergan Plc for more than $150 billion, making it the healthcare sector's largest deal ever, according to people familiar with the matter.
