The shells, which can offer companies a quick route to a public quote through a reverse takeover, had resources of £113.4 million at the end of June, according to research from growth company magazine Business XL.

Rob Smith is a serial AIM company finance director who has been involved in several reverse takeovers. He says that in the present ‘nervous’ market cash shells provide companies with an easier way to go public.

‘When you want to raise money by the traditional route you have to see around 100 fund managers and potential investors,’ Smith adds. ‘The attraction of a cash shell is that you only have to persuade two or three people.’

The study from Business XL reveals that among the 43 shells on AIM and PLUS, the five most cash-rich account for nearly three-quarters of the money. They are Clerkenwell Ventures, Cockleshell, Marwyn Materials, Aldgate Capital and Drury Lane Capital.

The leading advisers to shell companies are Alfred Henry Corporate Finance and Ruegg & Co, each of which represents five shells.