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STOCKHOLM, June 8 (Reuters) - Shares in Swedish rare diseases drugmaker Swedish Orphan Biovitrum (Sobi) tumbled on Monday after the company said it had terminated discussions over a possible offer for the company.
Sobi said in late April that it had received a preliminary bid proposal, with Pfizer identified by Reuters as the potential bidder.
The Swedish company's medicines for rare or "orphan" conditions make it a target in a consolidating sector in which large, cash-rich drugmakers are looking to bolster their portfolios with offerings from smaller biotech businesses.
Swedbank analyst Johan Unnerus said the company could continue to operate as a standalone business but a takeover may prove unavoidable.
"The market is so big I wouldn't be surprised if in the end they will be part of another company," he said, adding that Biogen would be a likely suitor.
A Sobi spokesman told Reuters that the recent talks were terminated because there had been no bid the board felt it could recommend to the owners but gave few further details.
"Sobi will continue to focus on preparations for the upcoming planned launch of (haemophilia drugs) Elocta and Alprolix and on building value through its diverse and growing portfolio," Sobi said in a statement.
The company's shares fell 16.4 percent to 109.80 Swedish crowns at 0858 GMT.
Reporting by Helena Soderpalm and Olof Swahnberg; Editing by David Goodman