Biotechnology firm Genentech has rejected Roche’s bid to buy the company out for $43.7 billion.

According to a statement released by Genentech, the offer put forward by Roche on July 21 for $89 per share, “substantially undervalues the company”.

The decision follows public announcements by analysts that the biotech company was worth in excess of $100 per share.

Roche already owns 55.9% of Genentech and in July made the announcement it wanted to take over the rest of the company.

At the time Roche had said: “we believe our offer is both fair and generous and provides an opportunity for all non-Roche Genentech shareholders to receive an immediate premium for all of their shares.” But analysts have since accused the firm of taking advantage of the credit crunch and poor market conditions for placing such a low bid.

However, the rejection does not spell the end for a possible buy out. Genentech’s special committee said it would still consider a proposal that “recognises the value of the company and reflects the significant benefits that would accrue to Roche as a result of full ownership”.

Special committee chairman Dr Charles Sanders said: “The special committee is confident in the company’s strong financial and clinical momentum and its uniquely productive R&D capabilities, which will continue to enhance shareholder value. In addition, we look forward to the company maintaining its successful relationship with Roche, regardless of ownership structure.”

Roche head media spokesman Daniel Piller told PharmaTimes the company “continued to believe that the proposal is fair and generous”.

He said that at this point there were no plans to go back to consider a higher bid.

He declined to comment further.