Biogen Idec Inc. said Friday its third-quarter net income rose 38 percent, as sales of key products like the Crohn's disease and multiple sclerosis treatment Tysabri rose and some expenses fell.

The Weston, Mass., company earned $351.8 million, or $1.43 per share, in the three months that ended Sept. 30. That compares to earnings of $254.1 million, or $1.05 per share, in the same quarter last year. Adjusted earnings were $1.61.

Revenue climbed 11 percent to $1.31 billion.

The performance topped Wall Street expectations. Analysts surveyed by FactSet expected, on average, earnings of $1.53 per share on $1.26 billion in revenue.

Biogen said revenue from Tysabri, which it markets through a partnership with Elan Corp. PLC of Ireland, rose 26 percent to $277 million Sales of another multiple sclerosis drug, Avonex, climbed 6 percent to $682 million. Royalties rose about 44 percent to $51.6 million.

The company's total cost and expenses fell 16 percent to $821.4 million, as research and development expenses fell.

Biogen still expects to earn "above $5.70" per share in 2011, excluding one-time costs, a forecast it also made when it announced second-quarter earnings in July. It forecasts revenue growth to be in the mid-single digits compared to 2010. Analysts had expected 2011 earnings of $5.88 per share on revenue of $4.96 billion, would represents growth of 5 percent from Biogen's revenue of $4.72 billion in 2010.

Shares of Biogen rose $1.53, or 1.3 percent, to $119.127 Friday afternoon.