Maverick investor Carl Icahn is preparing to mount a proxy bid for Yahoo, reports The Wall Street Journal.

Since Microsoft withdrew its bid for the company, Icahn has purchased 50 million Yahoo shares. He is expected to try erecting his own replacement board.

Icahn is known for inspiring companies to make "better" business decisions by threatening to oust their management. Previous corporate break-up attempts included Time Warner and Motorola. Last year he drove CEO John Anti-oco of Blockbuster to resign his post.

Icahn's current dissatisfaction Yahoo lies in its rejection of the Microsoft bid, which was speculated as more of a personal beef on Jerry Yang's part than a business decision.

Other investors are biding time to see where Icahn's proxy fight might lead. Some may join him while others remain content to watch from the sidelines, so long as the shake-up means Yahoo will reconsider the Microsoft offer.

Google recently emerged as a potential ad partner for Yahoo Search, but that relationship has already begun to generate scrutiny from cause groups and the Justice Department. Any such deal would only be subject to more investigation and outcry from antitrust and privacy advocates.