NEW YORK (Reuters) - The U.S. Securities and Exchange Commission on Tuesday denied for the second time this month a request to bring to market a first-of-its-kind product tracking bitcoin, the digital currency.

The SEC announced in a filing its decision denying Intercontinental Exchange Inc's NYSE Arca exchange the ability to list and trade the SolidX Bitcoin Trust, an exchange-traded product (ETP) that would trade like a stock and track the digital asset's price. Previously, the regulatory agency said it had concerns with a similar proposal by investors Cameron Winklevoss and Tyler Winklevoss.

"The Commission believes that the significant markets for bitcoin are unregulated," the SEC said in its filing, echoing language from its decision earlier this month on the application by CBOE Holdings Inc's Bats exchange to list The Bitcoin ETF proposed by the Winklevoss brothers. On Friday, Bats asked the SEC to review its decision not to allow that fund to trade.

"We are reviewing the SEC's order and evaluating our next steps," said Daniel H. Gallancy, chief executive officer of SolidX Partners Inc,