(Adds quotes and details on other companies, Aramco)
RIYADH, Oct 23 (Reuters) - Billionaire Saudi Prince Alwaleed bin Talal, who owns investment firm Kingdom Holding, expressed skepticism about cryptocurrencies in an interview with CNBC on Monday, warning that bitcoin was like "Enron in the making".
Prince Alwaleed, whose company invests in major U.S. companies such as Citigroup and Twitter, said a lack of regulation made such cryptocurrencies risky.
"I just don't believe in this bitcoin thing. I think it's going to implode one day. It's Enron in the making," he said, referring to the U.S. energy company that filed for bankruptcy in 2001 after revelations of a widespread accounting fraud.
"This thing does not make sense. It's unregulated. It's not under the control of the U.S. Federal Reserve or any other central bank," he added.
Bitcoin is a virtual currency that has gained more than 500 percent this year, more than any other tradable asset class.
Prince Alwaleed also said the valuation of electric car maker Tesla Inc was "too exuberant" for him to invest.
"I would rather not comment on that because maybe some people think the valuation is right, but it's not for me to enter that price obviously. It's too exuberant for me right now."
He added that U.S. ride services company Lyft had been better priced than rival Uber when his investment firm bought into it.
He said he was "very happy" with his investment in Citigroup and saw potential for the share price to rise above $100. It has been trading at around $73.
Prince Alwaleed also said he was not considering merging AccorHotels and Four Seasons Hotels and Resorts, in which Kingdom Holding owns stakes.
On the initial public offering of Saudi Aramco, which its CEO reiterated would take place next year, Prince Alwaleed said the transaction would act as a "safety valve" for Saudi Arabia.
"If you go 5 percent, there's nothing that prohibits you from going another 5 percent next year, and 5 percent the third year and fourth year, and so forth, depending on the situation."
Crown Prince Mohammed bin Salman said last year the country was considering listing about 5 percent of Aramco in a deal that could raise $100 billion, if the company is valued at about $2 trillion as hoped.
CEO Nasser on Monday brushed off reports about China emerging as a frontrunner in a possible plan to delay the IPO and sell shares to sovereign funds.
"I'm not a member of the government but I read these reports, and I will not be surprised if China will be looking at this opportunity," Prince Alwaleed said.
"China depends on oil and will depend on oil for a long time to come. And Saudi Arabia is an anchor exporter of oil to China." (Reporting by Katie Paul, Maha El Dahan, Alexander Cornwell and Reem Shamseddine; Writing by Sylvia Westall; Editing by David Holmes)