U.S. drugmaker Schering-Plough Corp said on Tuesday its second-quarter earnings rose after lower special charges, but global revenue declined as the weak dollar hurt sales in overseas markets.

The company, which is expected to be acquired by Merck & Co Inc in coming months, said net income available to common shareholders was $633 million, or 38 cents per share. That compared with $424 million, or 26 cents per share, in the year-earlier period, when the company took charges for its acquisition of Organon BioSciences.

Excluding items, Schering-Plough earned 46 cents per share. Analysts, on average, expected 45 cents per share, according to Reuters Estimates.

Company sales totaled $4.65 billion, higher than the Reuters Estimates expectation of $4.61 billion.

Sales of Schering-Plough's cholesterol drugs Zetia and Vytorin fell 8 percent to $1.1 billion in a continuing downturn after data from two clinical trials questioned the effectiveness of the medicines. It sells the two drugs in a joint venture with Merck.

Sales of Remicade, a widely used treatment for rheumatoid arthritis, rose 2 percent to $565 million.

(Reporting by Ransdell Pierson; editing by Jeffrey Benkoe)