Swiss biotechnology group Serono announced today that it has taken itself off the shelf after ending ongoing discussions with potential suitors over the sale of the major stake in the company.

The firm’s controlling shareholder, the Bertarelli family, which owns over 60% of the business, has indicated that it made the decision after a spate of disappointing offers that did not adequately reflect Serono’s future prospects. As a result, the company has changed track and is now keeping an eye out for any purchases that will help build its business.

“Moving forward, Serono will invest in its existing businesses and will actively pursue opportunities for growth through acquisitions,” said Ernesto Bertarelli, Serono’s Chief Executive Officer.

But shareholders were not impressed with the news, and the company’s stock had already fallen more than 9% to around 835 Swiss francs in early morning trading.

Rumours that Serono was putting itself up for sale first came to the fore in November last year, and analysts estimated that it could ask as much as $15 billion for the entire company. But poor interest in the group forced a lowering of the bride price to around $11 billion in January, pushing the group’s share price down to its lowest level in more than three years at the time.

Although quite a few big boys, such as Wyeth and Johnson & Johnson, were touted as potential buyers, the new price tag also failed to entice an acceptable offer. The purchase of Serono would grant access to its phenomenally successful multiple sclerosis drug Rebif (interferon beta-1b). But suitors were likely put off by the drug’s slowing sales, particularly in the US market, as well as a weakened pipeline in the wake of several product failures.