Genzyme started the jostling for AnorMED when it offered $8.50 a share. That bid was quickly rejected by AnorMED's board as it courted Millenium to step in and make an offer, which it did, at $13.
Genzyme reviewed Millenium's second offer and increased its own to the current $13.50.
Millenium's decision not to increase its offer a second time opens the door for other companies to take over AnorMED, if Genzyme's offer is not accepted.
Millenium also expects to recieve a payment of almost $20 million for breaking talks with AnorMED.
AnorMED's stem cell mobilizer Mozobil is at the heart of these takeover talks.