(Adds details on tax plan, Fink's views on bitcoin and markets)
NEW YORK, Oct 3 (Reuters) - BlackRock Inc Chief Executive Larry Fink on Tuesday said a U.S. tax plan backed by the Trump administration cannot be passed as it is, noting the proposal would add to the deficit.
"I think it's going to have to be amended," said Fink, whose company is the world's largest asset manager, in an interview with Bloomberg Television.
The Trump administration outlined a proposal last week that would provide $5.99 trillion in tax cuts while reducing federal revenues by a net $2.4 trillion in the next 10 years, according to a first detailed analysis of the plan by the non-profit Washington-based Tax Policy Center.
Fink said he is concerned that deficits could expand even as the U.S. elderly population grows, raising the cost of social-insurance programs and forcing the United States government to fund its spending by borrowing abroad.
He also said he opposes an element of the administration's proposal that would prevent taxpayers from deducting certain expenses, including levies paid to state and local governments.
While Fink said markets are fine and will do well until the end of the year, he noted that he sees more "value" outside the United States. BlackRock manages $5.7 trillion.
Fink said he expects Trump to nominate more "moderate" candidates to serve on the U.S. Federal Reserve than Republicans have in the past, likely portending no major changes in the direction of monetary policy.
Regarding a fierce debate over the utility of cryptocurrencies such as bitcoin, Fink described himself as "a big believer in the potential of what a cryptocurrency can do." But he added that the digital currencies are currently being used for "money laundering" and speculation.
JPMorgan Chase & Co Chief Executive Jamie Dimon last month said bitcoin, which has soared nearly 350 percent this year, "is a fraud" and will blow up. But Fidelity Investments struck a more optimistic note, starting its own bitcoin "mining" operation to create new coins.
Fink also said that BlackRock will ramp up its in-house investment research following new European Union rules due to go live in January 2018.
As part of the EU's Markets in Financial Instruments Directive II, or Mifid II, asset managers will have to agree on a price for all research obtained from brokers. Most research currently is given out for free, with brokers recouping the cost through fees on executing trades for fund managers. (Reporting by Trevor Hunnicutt; Editing by Chizu Nomiyama and Dan Grebler)