The latest research report from GrowthBusiness.co.uk, Cash Shells Directory 2012, uncovers 64 cash shells on AIM, PLUS and the Main Market of the London Stock Exchange (LSE), five more than in last year’s research.

Their total cash resources amount to £238 million, compared to £230 million last year. Most of this (85 per cent) is concentrated in the ten richest London-listed shells, all of which are AIM-listed.

Among the biggest shells is NBNK Investments, with £26.4 million in the bank and net current assets of £23.5 million. The company had hoped to acquire some former branches of Lloyds TSB, but these negotiations have concluded without success and NBNK’s shares, which had been suspended from AIM pending a possible reverse takeover, have now been readmitted to trading.

PLUS-quoted shells account for £7.5 million, or 3 per cent of the cash held by all shells. The most cash-rich is Rare Minerals, which has just over £1 million in the bank having joined PLUS in April last year to make acquisitions or investments in the energy or mining sectors.

The combined market capitalisation of shells on AIM, PLUS and the Main Market is £379 million, a premium of 59 per cent to their total cash holdings. However, the report from GrowthBusiness uncovers 13 shells trading at a discount to their net current assets, including Shellproof and Shellshock, two Belize-incorporated companies that are majority-owned by Conservative party donor and former deputy chairman Lord Ashcroft.

The number of cash shells on AIM peaked at 97 in 2006. In this year, the LSE changed the rules governing its junior market, forcing shells to make an acquisition or investment within three years or face expulsion from AIM. Mainly as a result of this, the number of AIM-quoted shells fell to 23 in 2007 and reached its nadir two years later, when there were only 12.

Since then, the number of shells on AIM has been on the increase, with 34 uncovered by this year’s research, in addition to 27 on PLUS and three on the Main Market of the LSE.