Xerox could combine with a competitor that is actually willing to pay a significant premium, or Japan's Fujifilm Holdings themselves would step up and offer a full buy-out on fair terms, the shareholders wrote in an open letter. (http://bit.ly/2Hvx51N)

The activist shareholders, who own a combined 15 percent of the U.S. printer and copier maker, have repeatedly urged shareholders to oppose the Fuji-Xerox deal.

Icahn and Deason said last week the agreement dramatically undervalued Xerox, and criticized the deal structure calling it "tortured, convoluted".

"Carl Icahn and Darwin Deason's letter is consistent with their misguided campaign to undermine Xerox's combination with Fuji Xerox," Xerox said in a statement on Tuesday.

The company reiterated that among the range of strategic options, combination with Fuji Xerox is the superior path forward for Xerox.

On Jan. 31, Fujifilm said it was set to take over Xerox in a $6.1 billion deal and combine it into their existing joint venture, Fuji Xerox.

Shares of Xerox were up nearly 1 percent.

(Reporting by Supantha Mukherjee and Sonam Rai in Bengaluru; Editing by Bernard Orr)