Bristol-Myers Squibb Co on Tuesday named Chief Operating Officer Lamberto Andreotti, 59, to succeed James Cornelius as its chief executive officer, effective May 4.

Cornelius, 66, who took over the helm of the U.S. drugmaker in 2006 after longtime CEO Peter Dolan lost favor with Wall Street, will remain as chairman, the company said.

Andreotti's profile as a possible successor to Cornelius was significantly raised last March, when he was promoted to president and elected to the board of directors. He had already been COO and was responsible for the global pharmaceutical business.

Separately last year, Andreotti, research chief Elliott Sigal, and Chief Financial Officer Jean-Marc Huet were appointed to sit with Cornelius on the Executive Committee, making them all potential candidates to become the next CEO.

Lamberto has demonstrated extraordinary leadership as president and chief operating officer and I believe he is the natural candidate to replace me as CEO, Cornelius said in a statement.

Among the significant hurdles facing Andreotti as he takes control will be steering the company through the 2012 patent expiration of the blood clot preventer Plavix -- the $8 billion a year drug it shares with French drugmaker Sanofi-Aventis

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While challenges lie ahead, we are confident we can overcome them, Andreotti said in a statement.

(Reporting by Bill Berkrot; Editing by Richard Chang)