Icahn's an Energizer Pit Bull

For a 73-year-old man, Carl Icahn sure has some stamina. After failing to get Biogen Idec (Nasdaq: BIIB  ) sold in late 2007, and losing a proxy fight last year, the billionaire activist investor is at it again. He's proposed a new set of nominees for the board and is now floating the idea of splitting the company in two.

Icahn better hope investors have his endurance. He's filed a slide deck -- 52 slides long -- with the Securities and Exchange Commission to try and convince investors that he can bring out value that management has squandered. There's a lot of good information in there, but investors may be turned off by the length and the ego stroking about how Icahn and his associates successfully increased the value of ImClone Systems and got Eli Lilly (NYSE: LLY  ) to outbid Bristol-Myers Squibb (NYSE: BMY  ) for the privilege of owning his masterpiece. He didn't actually say that, but that's the way it comes across.

If the goal is to get Biogen Idec sold, then splitting the company into a neurology-focused and a cancer-focused company seems pretty reasonable. Biogen Idec probably didn't get any definitive offers when it put itself up for sale in 2007, because of its multiple partnerships with different companies. Splitting the company would fix that by separating the Tysabri partnership with Elan (NYSE: ELN  ) from Biogen's Rituxan partnership with Roche.

The split would make it easier to sell, but I'm not sure it will result in Icahn's goal of unleashing the pent-up value. Roche might be willing to buy the cancer-focused offspring, but it may be hard to get a bidding war going with the change of control provision that allows Roche to buy out Biogen Idec's half of Rituxan. The neurology-focused half of the company might attract a few bidders, but only if they can work out a deal with Elan to hold onto Tysabri before they sign the final papers -- something Icahn claims management didn't let potential bidders do in the past.

Between a fight with Amylin Pharmaceuticals' (Nasdaq: AMLN  ) management and dealing with his other investments like Yahoo! (Nasdaq: YHOO  ) , Icahn sure does have a lot on his plate. Investors probably shouldn't try to emulate him -- pick someone like Warren Buffett instead -- but they should cheer him on. At the very least, it's entertaining, and the pressure he puts on management might result in some positive changes at Biogen.