May 21 (Reuters) - The U.S. securities regulator on

Monday asked Nasdaq and CBOE to fine-tune their applications to

list spot ether exchange-traded-funds (ETFs), signaling the

agency may be poised to approve the filings, three people

familiar with the process told Reuters.

While the exchange applications are the first step in a

two-step approval process, a Securities and Exchange Commission

green light would mark a major -- surprise -- win for the

cryptocurrency industry that had been expecting the thumbs-down.

The price of ether jumped as much as 18% Monday, and was up

another 2.5% at $3,764 early Tuesday morning.

The SEC must decide whether to approve applications filed by

CBOE to list ether ETFs provided by VanEck and ARK

Investments/21Shares by the end of this week. The SEC had not

engaged with exchanges and issuers on the filing details,

leading industry executives to expect a thumbs-down.

But in a surprise move, SEC officials on Monday asked Nasdaq

and CBOE to quickly make updates and changes to the filings,

requests which usually precede approval, said the people who

declined to be identified discussing private regulatory matters.

Spokespeople for the SEC and CBOE declined to comment.

Spokespeople for Nasdaq and ARK did not return a request for

comment.

Reuters could not immediately verify if NYSE Arca, the third

exchange involved, had also been contacted by the SEC.

The exchange applications seek SEC approval for a rule

change required to list new products, but the issuers still need

the agency to approve the ETF registration statements before

they can start trading.

Unlike the exchange filings, there is no set time frame in

which the SEC has to decide, meaning it could still take several

months for ether ETFs to being trading.