Raul Kohan Appointed CEO of New Animal Health Joint Venture

July 28, 2010 – Sanofi-aventis and Merck & Co., Inc. announced yesterday that Raul E. Kohan will be appointed Chief Executive Officer of their proposed Animal Health joint venture. Sanofi-aventis and Merck – known as MSD outside the United States and Canada – intend to combine Merial with Intervet/Schering-Plough, to create a new global leader in Animal Health to be called Merial-Intervet.

July 28, 2010 – Sanofi-aventis and
Merck & Co., Inc. announced yesterday that Raul E. Kohan will be
appointed Chief Executive Officer of their proposed Animal Health joint
venture. Sanofi-aventis and Merck – known as MSD outside the United
States and Canada – intend to combine Merial with
Intervet/Schering-Plough, to create a new global leader in Animal
Health to be called Merial-Intervet.

Mr. Kohan is currently President of Intervet/Schering-Plough, Merck's Animal Health business. He will commence his new responsibilities when the new joint venture is approved by regulatory authorities and closes, which is expected to occur in the first quarter of 2011.

The formation of this new animal health joint venture is subject to execution of final agreements, antitrust review in the United States, Europe and other countries, as well as other customary closing conditions.

Raul Kohan is Executive Vice President and President, Global Animal Health, Merck. He joined
Schering-Plough in 1984 and has since held positions of increasing responsibility. He served as
Deputy Head of Animal Health and Senior Vice President, Corporate Excellence and Administrative
Services for Schering-Plough Corporation. Previously, Kohan’s responsibilities included overseeing
the company's Global Specialty Operations group, which comprised Animal Health and Consumer
Health Care for Schering-Plough. Kohan graduated from the General San Martin Military Academy,
Argentina, and holds an M.B.A. degree in economics from the University of Buenos Aires.

José Barella, the current Executive Chairman of Merial, will continue his role until the transaction
closes. Thus, he will work closely with Mr. Kohan and will contribute significantly to the transition and
creation of the new combined Animal Health business. Mr. Barella joined Merial in 2001 and became
Chief Operating Officer in 2005 and head of business operations with responsibilities for all
commercial activities for Merial globally, including sales and marketing for both the companion animal
and production animal businesses, and the commercial functions that support them. He was named
Merial's Executive Chairman in 2007 with responsibility for executing global strategy and through his
leadership grew the company to be an industry leader.

The new Merial-Intervet joint venture will offer a broader portfolio of animal health products and
services in pharmaceuticals and biologics, as well as, the ability to capitalize on growth opportunities
in all fields and countries around the world.

The worldwide animal health market reached $19 billion in 2008. Products for companion animals
accounted for 40 percent of total sales while products for production animals accounted for the
remaining 60 percent of total sales. This market is expected to grow at around 5 percent per year
over the next 5 years, driven by a growing demand for animal proteins, as well as a strong consumer
needs for companion animal health care.

Merial and Intervet/Schering-Plough will continue to operate independently until the closing of the
transaction.