A view of the Schering-Plough campus in Kenilworth, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. REUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH)

A view of the Schering-Plough campus in Kenilworth, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. ÊREUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH)

A view of the Merck & Co. campus in Linden, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. REUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH)

A view of the Merck & Co. campus in Linden, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. ÊREUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH)

A view of the Merck & Co. campus in Linden, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. REUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH)

A view of the Merck & Co. campus in Linden, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. REUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH)

A view of the Merck & Co. campus in Linden, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. REUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH IMAGE OF THE DAY TOP PICTURE)

A view of the Schering-Plough campus in Kenilworth, New Jersey March 9, 2009, after Merck & Co Inc said it would acquire Schering-Plough Corp in $41.1 billion deal, widening Merck's pipeline and diversifying its portfolio of medicines. REUTERS/Jeff Zelevansky (UNITED STATES BUSINESS HEALTH IMAGE OF THE DAY TOP PICTURE)

A sample of the drug Singulair made by Merck & Co. Inc. is seen in New York March 9, 2009. Merck & Co Inc announced it would acquire Schering-Plough Corp for $41 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Chip East (UNITED STATES HEALTH BUSINESS)

A sample of the drug Singulair made by Merck & Co. Inc. is seen in New York March 9, 2009. Merck & Co Inc announced it would acquire Schering-Plough Corp for $41 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Chip East (UNITED STATES HEALTH BUSINESS)

A sample of the drug Nasonex made by the Schering Corporation is seen in New York, March 9, 2009. Merck & Co Inc announced it would acquire Schering-Plough Corp for $41 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Chip East (UNITED STATES HEALTH)

A sample of the drug Proventil made by Schering Corporation is seen in New York March 9, 2009. Merck & Co Inc announced it would acquire Schering-Plough Corp for $41 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Chip East (UNITED STATES HEALTH)

A sample of the drug Nasonex made by the Schering Corporation is seen in New York March 9, 2009. Merck & Co Inc announced it would acquire Schering-Plough Corp for $41 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Chip East (UNITED STATES HEALTH BUSINESS)

A sample of the drug Nasonex, made by the Schering Corporation, is seen in New York, March 9, 2009. Merck & Co Inc announced it would acquire Schering-Plough Corp for $41 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Chip East (UNITED STATES BUSINESS HEALTH)

Richard Clark, Chairman and C.E.O. of Merck, speaks at the Reuters Health Summit in New York, in this file photo taken November 19, 2008. Merck & Co Inc. said on March 9, 2009 that it would acquire Schering-Plough Corp for $41.1 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Brendan McDermid/Files (UNITED STATES BUSINESS HEALTH SCI TECH HEADSHOT)

Richard Clark, Chairman and C.E.O. of Merck, speaks at the Reuters Health Summit in New York, in this file image taken November 19, 2008. Merck & Co Inc. said on March 9, 2009 that it would acquire Schering-Plough Corp for $41.1 billion, uniting the makers of cholesterol drugs Zetia and Vytorin in the second megadeal for Big Pharma in weeks. REUTERS/Brendan McDermid/Files (UNITED STATES BUSINESS HEADSHOT HEALTH SCI TECH)