Biogen Idec Inc., a Weston company known for its multiple sclerosis drugs such as Avonex and Tysabri, said Monday that its fourth-quarter revenues rose 7 percent on a year-to-year basis to $1.4 billion.

Fourth-quarter 2012 GAAP diluted earnings per share were $1.23, an increase of 1 percent over the fourth quarter of 2011. GAAP net income attributable to Biogen Idec for the quarter was $292 million, a decrease of 3 percent from the fourth quarter of 2011.