NEW YORK, April 24 (Reuters) - Allergan Inc approached Shire Plc in recent months about a possible takeover but was rebuffed, according to people familiar with the matter, in the latest example of a U.S. drugmaker seeking to buy an overseas rival to lower its tax rate.
The preliminary approach for Shire, which is based in Ireland and has a market value of $33 billion, did not progress to serious discussions between the two companies, the sources said.
Since then Allergan has received an unsolicited $47 billion takeover offer from Valeant Pharmaceuticals International Inc teamed up with activist investor Bill Ackman's Pershing Square Capital Management.
Analysts have suggested one way for the Botox maker to defend against the unsolicited bid would be to acquire foreign drugmakers such as Shire, Jazz Pharmaceuticals Plc or Alkermes Plc.
One of the sources said it was unclear if Allergan would try to revive talks with Shire, or pursue another target as a means to remain independent.
Representatives for Allergan and Shire declined to comment.
(Reporting by Olivia Oran, Soyoung Kim and Nadia Damouni in New York; Editing by Lisa Shumaker)