Bookmaker Stuart Wheeler, the founder of IG Group, is a betting man but even he must be concerned at the odd situation that the company has found itself as his rivals run a grey market on the likely success of his company's flotation.

City Index and Cantor Fitzgerald, also financial spread betting groups, are offering a grey market on IG's shares of 262p-272p and 272p-277p each.

IG, the parent company of IG Index, has priced its shares at 240p each, valuing the company at £125.5m.

The original backers of the company who invested in the operation started in 1974 with £300 have seen their stake multiply to about £12.5m.

IG Index spokesman Paul Austin said that while legally the group was restricted from offering a grey market in its own shares, there was a more important reason for choosing not to do so.

"It would be too embarrass ing if we got it wrong," he said. "We expected to be under the microscope as the offer seems to have drawn a lot of interest."

Financial Spreads is one bookmaker which is not offering a grey market on IG Group which intends to list on July 19.

"Obviously they are another interesting company that is about to float and obviously one that's close to our heart," said Simon Mansell, managing director at City Index. "It's a little bit more fun when it's one of the competitors."

David Buik, marketing director at Cantor Fitzgerald, said it was in the betting industry's interests that IG Group float went well.

Mr Wheeler is expected to own about 33% of the listed group after cashing in about 10% of his holding for £5m.

IG Group is raising just £1.15m net of expenses through a placing of 833,333 shares.

The funds will be used for working capital and acquisitions.

• Business