PITTSBURGH (AP) — Generic drug maker Mylan Inc. said today that its first-quarter profit rose 71 percent, mainly on increasing drug sales in North America.

The company earned $104.2 million, or 23 cents per share, for the three months ended March 31, up from $61.1 million, or 20 cents per share, a year ago. The most recent quarter included an additional 136.5 million shares of stock outstanding.

Revenue rose 12 percent to $1.45 billion.

Excluding charges, including purchase accounting items and litigation expenses, the company said it earned 44 cents per share, matching expectations of analysts polled by FactSet. Analysts expected revenue of about $1.43 billion.

Generic drug revenue rose 12 percent to $1.34 billion during the quarter, driven by volume in North America. Specialty drug revenue rose 17 percent to $97 million.

Looking ahead, the company reaffirmed 2011 profit guidance between $1.90 and $2.10 per share. In February, the company also said it expects revenue between $6.1 billion and $6.4 billion. Analysts expect profit of about $2.01 per share on revenue of about $6.1 billion

Also, Mylan said its board of directors approved a $350 million stock buyback program, which is expected to be completed by June 30.