Sanofi (NYSE:SNY) is reportedly considering a bid for Actelion Pharmaceuticals (VTX:ATLN), competing with an offer made to the Swiss biotech by Johnson & Johnson (NYSE:JNJ). Bloomberg reported that Sanofi is working with advisers to assess its options and has made its interest known informally to Actelion. The French drugmaker has not made a formal comment on the matter and has not decided if it will move forward with a bid.

J&J has been in talks with Actelion about what reports have said may be a $27 billion takeover bid. The high premium offer is tempting to shareholders, who would rather take the cash now than bet on Actelion CEO Jean-Paul Clozel’s risky pipeline for therapeutics targeting rare diseases.

Actelion shares opened up by 4% and were trading at 207.30 Swiss francs in mid-morning activity today, up 2.3%.

Advisers for Sanofi have reportedly reached out to drugmakers Roche (PINK:RHHBY) and Pfizer (NYSE:PFE) to assess the potential interest for Actelion. Sanofi may be eager to compete for Actelion, since it lost out on a deal to buy Medivation Inc. earlier this year, which gave Pfizer a “blockbuster prostate cancer treatment”, according to Bloomberg. CEO Olivier Brandicourt said that the company would be ready to “act rather swiftly” should a new opportunity for acquisition arise.

J&J and Sanofi won’t have to worry about a counterbid from Novartis (NYSE:NVS), as CEO Joe Jimenez said in an interview this week that the Swiss drugmaker is looking for acquisitions of less than $5 billion.

For either company, closing a deal will mean winning over Clozel, who has repeatedly asserted his company’s independence. In 2011, the CEO and co-founder rallied shareholders against an investor’s plan to sell the firm and 4 years later, he fought off interest from drugmaker Shire.

“If I look at the (drugs) pipeline that Mr. Clozel is excited about, I am perhaps less excited about it and see perhaps a greater risk than reward,” Union Bancaire Privee fund manager Eleanor Taylor Jolidon told Reuters. Union Bancaire Privee is among the top 40 investors in Actelion and holds 0.23% of outstanding shares. Jolidon said than an offer of 250 francs per share would be very enticing and that if Clozel rejected the bid, then “he would have a lot of explaining to do.”