UPDATE 1-Icahn calls new Bristol bid for ImClone "absurd"

BOSTON, Sept. 23 (Reuters) - Carl Icahn, the billionaire investor and chairman of biotechnology company ImClone Systems Inc IMCL.O fired off a letter to the chief executive of Bristol-Myers Squibb Co (BMY.N), calling Bristol's revised take-over offer of $62 a share "absurd."

The letter, printed in a press release on Tuesday, came in response to a sweetened, $62-a-share offer by Bristol for the 83 percent of ImClone it does not already own. Bristol previously offered $60 a share.

In a letter on Monday to Icahn, Bristol Chairman and CEO James Cornelius said ImClone's actions in refusing to accept Bristol's earlier bid had created "a protracted period of uncertainty" among stockholders that could hurt the intrinsic value of ImClone's asset.

Bristol also said it would file with the SEC a bid to remove all existing members of ImClone's board and replace them with its own candidates.

Icahn has said an unnamed third party has offered to acquire ImClone for $70 a share, subject to an indepth analysis, or due diligence.

Icahn said in his letter that the due diligence period will be over on Sunday, September 28th.

"Your hostile tender of $62, at this time, seems absurd," Icahn said in his letter. "If you wish to make your attorneys wealthier, I can show you more productive ways to do so. Or, if you simply want publicity, I can also help you in that regard without your having to make unnecessary expenditures."

ImClone, which makes the cancer drug Erbitux, co-markets the drug in the U.S. with Bristol. It's partner in Europe is Merck KGaA (MRCG.DE).

(Reporting by Toni Clarke; Editing by Bernard Orr)