PARIS, June 25 — US biopharmacy company AbbVie said today it had agreed to buy Allergan, the maker of Botox, in a stock and cash operation worth about US$63 billion.

The offer represents a 45 per cent premium over yesterday’s share price of Irish-registered Allergan, whose management recommended the operation to shareholders.

The deal, which AbbVie CEO Richard Gonzalez called "transformational”, is to close early in 2020.

The combined companies will generate around US$48 billion in revenues this year, AbbVie said.

"Combining Allergan’s diversified on-market product portfolio with AbbVie’s growth platform and deep expertise in R&D, commercial strength and international footprint will create a leading biopharmaceutical company,” it said.

The new company would boost earnings per share by 10 per cent in its first year, the US company predicted.

AbbVie’s main areas of expertise are immunology, oncology, virology and neuroscience.

Allergan, best known for the hugely popular cosmetic treatment Botox, specialises in the areas of medical aesthetics, eye care, central nervous system and gastroenterology.

Its portfolio also includes Humira, a best-selling treatment for rheumatoid arthritis. — AFP