When Roche of Switzerland announced plans for a $44bn buy-out of minorities in its US subsidiary Genentech this year, there were philosophical questions about how far the deal would stifle the entrepreneurial spirit and profits that the current arms-length structure has generated. The state of the financial markets has since cast a shadow even over the practicalities of funding the acquisition.

Roche’s voting shares are tightly held by a group of family investors. Their reluctance to give up control – especially with the company’s rival, Novartis, already holding only a fraction less than a third of the voting shares – means it almost certainly cannot raise money through a rights issue, even if investors were supportive.