Actavis Plc is in talks to buy Allergan Inc. for at least $60 billion in a deal that could culminate this month, Bloomberg reported, citing sources familiar with the matter.

The two companies are trying to narrow a gap of about $3 billion between what Actavis wants to pay and what Allergan is asking for, Bloomberg reported.

Allergan, which is trying to fend off a hostile takeover bid from Canadian drugmaker Valeant Pharmaceuticals International Inc, on Wednesday changed its bylaws associated with calling a special shareholder meeting.