TPG Capital LP has been exploring a sale of Aptalis Pharma, a specialty drugmaker it has owned since 2008 and values at more than $3 billion, four people familiar with the matter said on Wednesday.

The private equity firm has been working with JPMorgan Chase & Co and Evercore Partners Inc to find a buyer for the Montreal-based drugmaker in a sale process that has been under way for several months, said the sources, who asked not to be named because the matter is confidential.

A number of potential buyers, however, thought TPG's asking price of more than $3 billion was too high and decided not to bid, and it remains unclear if there will be a deal, two of the sources said.

Raleigh, North Carolina-based Salix Pharmaceuticals and Indian drugmaker Sun Pharmaceutical Industries Ltd are among the companies that passed on bidding after taking a look, the sources said.

Representatives for TPG, Aptalis and Sun Pharma did not immediately respond to requests for comment. Salix, JPMorgan and Evercore declined to comment.

(Reporting by Jessica Toonkel and Soyoung Kim in New York; Editing by John Wallace)