FILE PHOTO - Goldman Sachs Chairman and CEO Lloyd Blankfein speaks at the Bloomberg Global Business Forum in New York, U.S., September 20, 2017. REUTERS/Brendan McDermid

(Reuters) - Goldman Sachs Group Inc GS.N Chief Executive Lloyd Blankfein said he is keeping an open mind on bitcoin after a media report that the investment bank was exploring a new trading operation dedicated to cryptocurrencies.

"Still thinking about #Bitcoin. No conclusion - not endorsing/rejecting. Know that folks also were skeptical when paper money displaced gold," Blankfein tweeted on Tuesday. (bit.ly/2xP543l)

The plan is in early stages and may not proceed, the Wall Street Journal report on Monday, citing people familiar with the matter. (on.wsj.com/2xMdWq8)

Blankfein's tweet is in sharp contrast to comments made by JPMorgan Chase & Co JPM.N CEO Jamie Dimon, who called bitcoin a "fraud."

Bitcoin is a digital currency that enables individuals to transfer value to each other and pay for goods and services bypassing banks. The market is fraught with volatility, with bitcoin prices BTC=BTSP topping nearly $5,000 in early September and then declining sharply after Chinese authorities said they would ban the process of raising funds through launches of token-based digital currencies.

Speaking at a bank investor conference in New York last month, Dimon said, “The currency isn’t going to work. You can’t have a business where people can invent a currency out of thin air and think that people who are buying it are really smart.”

“It is worse than tulips bulbs,” Dimon said, referring to a famous market bubble from the 1600s.

Goldman's arch rival Morgan Stanley MS.N spoke in favor of the currency, with CEO James Gorman calling it "more than just a fad." (on.ft.com/2xMStNS)

Former Fortress Investment Group LLC executive Mike Novogratz is also starting a $500 million hedge fund to invest in digital currencies like bitcoin.