Biotechnology company Biogen Idec Inc. said Tuesday its third-quarter profit surged on strong drug sales to beat Wall Street expectations, and raised guidance for the full year.

Net income grew to $156.6 million, or 45 cents per share, from $27.2 million, or 8 cents per share, a year ago, when the company incurred hefty merger and restructuring costs. Excluding one-time charges and stock option expenses, the company reported a profit of 60 cents per share for the latest quarter.

Revenue rose 18 percent to $703.5 million from $596.2 million last year, driven by sales of interferon drug Avonex, which grew 19 percent to $445 million, and sales of arthritis treatment Rituxan, which increased by 12 percent to $204 million from last year.

Analysts surveyed by Thomson Financial expected earnings per share of 49 cents on revenue of $681.3 million. Estimates exclude both one-time charges and stock option expenses.

Biogen Idec also raised its earnings per share guidance above $2.20 for the year, excluding items. Previously, the company forecast earnings of $1.95 to $2.10. Analysts forecast earnings per share of $2.09.