International Ltd., approved a "poison pill'' Monday, according to Bloomberg business news service.

CellPro's poison pill defence -- a strategic move by a takeover target making its stock less attractive and a takeover more expensive -- comes in the form of a dividend of preferred share purchase rights to shareholders of record May 8.

Corange, a multi-billion-dollar pharmaceutical and health care concern and parent of Boehringer Mannheim and DuPuy Orthopaedics, and CellPro had entered into an agreement that would see the Bermuda company commit $110 million to CellPro through the purchase of the firm's common stock.

But according to CellPro, Corange will not complete the deal with a $60-million purchase of CellPro stock scheduled for later this month because a new Corange administration now believes a collaboration to develop a bone marrow purification device violates European antitrust laws.

CellPro's shares have plunged 50 percent since December 1, 1994 after trading as high as $20.50 on that date.

The poison pill, which will dilute the company's stock, was not enacted in response to an actual offer for the US biotechnology company, said Cellpro spokesman Mr. Lee Parker.

CellPro, with 13.1 million shares outstanding, has $65 million in the bank, equivalent to $5 per share.

"Sitting on all that cash, the poison pill gives them flexibility to control their destiny,'' said biotech analyst Ms Paula Szoka, publisher of the Independent Analyst. Without it the company's cash hoards makes it vulnerable to a hostile takeover, she added.

If there is a takeover the rights permit CellPro shareholders to buy shares in the acquiring company at a 50 percent discount. The rights can be exercised only if a person or group acquires or tenders to buy at least 15 percent of CellPro's shares.

The Corange development as well as two other company incidents have hurt CellPro's share prices.

On December 29, the Food and Drug Administration denied approval for its flagship Ceprate SC bone marrow purification system for treatment of women with advanced breast cancer then on March 14, Mr. Ronald Berenson, chief technology officer and inventor of the Ceprate system, resigned.