The companies are not currently in formal talks and Pfizer has not made an offer, the Bloomberg report said.

Pfizer in May abandoned its attempt to buy British drugmaker AstraZeneca Plc for nearly 70 billion pounds.

Actavis, which has a market capitalization of about $63 billion (38.4 billion pounds), obtained an Irish tax domicile by acquiring Warner Chilcott Plc last year.

Tough new U.S. rules on corporate "inversions" on Tuesday sent a chill through the market for the tax-avoidance deals, both pending and potential.

(Reporting by Ankur Banerjee in Bangalore; Editing by Sriraj Kalluvila)

Stocks treated in this article : Pfizer Inc., AstraZeneca plc, Actavis PLC