Billionaire investor Carl Icahn on Thursday urged Xerox Corp. to revise or even terminate its Fuji Xerox joint venture in the wake of an accounting scandal, and offered his support to Darwin Deason, the company's third-biggest shareholder. Deason said Wednesday that Xerox should disclose its agreement with Fuji and explore strategic alternatives regarding Fuji. "We are obviously in favor of renegotiating the joint venture agreement to make it more favorable for Xerox," Icahn wrote in an open letter to shareholders. "This should have been done a long, long time ago.