No precise reason was given by the representatives, though one said the company still planned to list eventually and was weighing up "alternatives" to AIM.

Coinsilium is one of many companies investing in the so-called blockchain technology that underpins bitcoin.

Blockchain is essentially a massive ledger of every bitcoin transaction ever made, verified and shared by a global network of computers.

Big names from IBM (>> International Business Machines Corp.) to NASDAQ (>> NASDAQ OMX Group, Inc.) are among those exploring how blockchain could be applied to financial markets.

Coinsilium chief Eddy Travia had told news outlets in July that the company's initial public offering (IPO) was planned for August and would raise around 3 million pounds ($4.6 million) to expand investments. Coinsilium has at least ten different investments in its portfolio, according to its website.

"It (the IPO) has not happened," a spokeswoman told Reuters, declining to give more information.

Luke Cairns, founder of advisory firm LSC Advisory who works with Coinsilium, said the company still planned to list eventually.

"(Coinsilium) is still planning to go ahead with an IPO but is weighing options, alternatives to AIM," he said.

SI Capital, named as company stockbrokers on Coinsilium's website, did not respond to requests for comment.

One reason for the delay may be last month's market turmoil. Financial market volatility surged to its highest level since the 2008-2009 crisis, as worries over China's economic slowdown and a worsening global growth outlook triggered stock market losses worldwide that have only partially been recovered since.

Analysts and industry watchers have said the market turmoil could slow already cooling appetite for IPOs.

(Reporting by Lionel Laurent; Editing by Mark Potter)

By Lionel Laurent