WHITEHOUSE STATION, N.J. (AP) — Merck & Co. says its second-quarter profit fell by half because of generic competition cutting into sales and acquisition and other charges.

The maker of blockbuster diabetes pill Januvia and Gardasil, a vaccine against sexually transmitted cancers, says second-quarter net income was $906 million, or 30 cents per share, down from $1.79 billion, or 58 cents per share, a year earlier.

Excluding one-time items, the world’s third-biggest drugmaker says adjusted net income was $2.53 billion, or 84 cents per share. Analysts surveyed by FactSet expected 82 cents.

Merck, based in Whitehouse Station, N.J., says revenue totaled $11.01 billion, down 11 percent. Analysts expected slightly higher sales of $11.24 billion.

The company backed its previous 2013 profit forecast for earnings per share of $1.84 to $2.05, excluding one-time items.