June 19 (Reuters) - The U.S. Securities and Exchange Commission has closed its investigation into the blockchain protocol Ethereum 2.0, cryptocurrency firm Consensys said in a post on social media platform X late on Tuesday.

The firm filed a lawsuit seeking an injunction against the U.S. SEC in April over regulation of the Ethereum blockchain.

Consensys founder Joseph Lubin said on Wednesday that SEC's decision to close the inquiry marked "a significant victory" for Ethereum.

"While we welcome this development, it's not enough. We must remain vigilant and continue advocating for clear and fair regulations that enable innovation to flourish," Lubin, who also co-founded the cryptocurrency ether, said in a post on X.

Consensys said it will continue its lawsuit in pursuit of a court ruling that the SEC does not have legal authority to regulate the user-controlled software interfaces built on Ethereum or the Ethereum blockchain.

The SEC was not immediately available for comment due to a federal holiday.

The SEC last month approved applications from Nasdaq, CBOE and NYSE to list spot ether ETFs. It was a surprise win for the cryptocurrency industry which had expected the SEC to reject the filings. (Reporting by Bhanvi Satija in Bengaluru; Editing by Cynthia Osterman)