Icahn bought 6.3 mln Amylin shares in Q1: filing

WASHINGTON (Reuters) - Investor Carl Icahn bought 6.3 million shares of Amylin Pharmaceuticals Inc (AMLN.O: Quote, Profile, Research) in the first quarter of 2008 and also boosted his stake in Biogen Idec Inc (BIIB.O: Quote, Profile, Research) during that time period, according to documents Icahn filed with the U.S. Securities and Exchange Commission.

Icahn held 9.9 million shares of Biogen on March 31, up from 8.3 million shares on December 31, according to the filing.

The billionaire investor is seeking to nominate three directors to Biogen's board of directors in a proxy fight that Biogen says is aimed at forcing a sale of the Cambridge, Massachusetts-based company. Biogen put itself up for sale in October but ended the auction in December after failing to attract bidders.

Icahn did not own any shares of Amylin at the end of 2007. Both Amylin and Biogen are biotechnology companies.

Amylin shares were up 68 cents or more than 2 percent at $31.32 in midday trading on Nasdaq, after trading as high as $32.78 earlier. Biogen shares were up 16 cents to $63.06.

The quarterly filing showing Icahn's holdings at the end of the first quarter was posted on the Internet at: here

(Reporting by Julie Vorman, editing by Dave Zimmerman)