Embattled biotechnology firm ImClone Systems Inc., urged its shareholders once again on Friday to reject a proposal by billionaire financier, Carl Icahn, who wants to remove four board members following the resignation of two others earlier this week.

ImClone’s board of directors agree that Ichan’s proposal will not in the interest of shareholders and has taken action by mailing a letter to all its shareholders which includes a list of its definitive proxy materials.

“If he succeeds, Mr. Icahn and a handful of directors who were selected by and/or have ties to him would constitute five of seven ImClone Systems' directors, a result… would give Mr. Icahn unfettered control of your Company,” the letter read.

“Shouldn't you at least insist that he pay you a control premium before handing him control of the Company?” ImClone said.

ImClone's chairman and another director resigned earlier this week amid pressure by Icahn, who insists that new management would allow the company to reap more value from its cancer drub Erbitux. ImClone markets the drug with Bristol-Myers Squibb Co.