(Adds details, shares)

Oct 26 (Reuters) - Biogen Inc BIIB.O reported a better-than-expected quarterly profit driven by sales of its multiple sclerosis drugs, sending its shares up in premarket trading.

Shares of the company, which in July said Chief Executive George Scangos would step down once a successor is named, were up 2.10 percent at $292.

The company has been focusing on core areas, such as neurology, with high-risk, potentially high-reward experimental treatments for Alzheimer's among others.

Net income attributable rose to $1.03 billion, or $4.71 per share, in the third quarter ended Sept. 30, from $965.6 million, or $4.15 per share, a year earlier.

Excluding special items, Biogen earned $5.19 per share, well above analysts' estimates of $4.97 per share, according to Thomson Reuters I/B/E/S.

Third-quarter sales of the U.S. biotechnology company's bestseller Tecfidera, came in at $1.03 billion, nudging past analysts' consensus of $1 billion, according to Barclays.

Total revenue rose 6 percent to $2.96 billion, just ahead of estimates of $2.91 billion.

(Reporting by Ankur Banerjee in Bengaluru; Editing by Shounak Dasgupta) ((ankur.banerjee@thomsonreuters.com; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 6132; RM: ankur.banerjee.thomsonreuters.com@reuters.net))