Teva Pharmaceutical Industries is to sell Allergan's generics business in the UK and Ireland to India's Intas Pharmaceuticals for £603m.
The sale was part of Teva's deal with the European Commission to get approval for the acquisition of Allergan's generics business, called Actavis Generics.
The company said it expected the sale to close in the next three months.
Teva completed the $40.5-billion acquisition of Allergan's generics business in August.
Actavis, which closed its $70.5 billion acquisition of Allergan in May 2015, had retained the Allergan name.