(Reuters) -The U.S. Securities and Exchange Commission has given preliminary approval to at least three of the eight asset managers hoping to launch exchange-traded funds tied to the spot price of ether to begin trading next Tuesday, three industry sources said.

The approval hinges on applicants submitting final offering documents to regulators before the end of this week, the sources said. One said that all eight are expected to launch simultaneously. The SEC didn't immediately respond to requests for comment.

Following the launch of nine U.S. spot bitcoin ETFs in January, the ether products would mark another major win for the cryptocurrency industry's campaign to push digital assets into the mainstream. Ether is the world's second largest cryptocurrency after bitcoin.

BlackRock, VanEck and Franklin Templeton are among the eight asset managers whose applications are likely to be greenlit by the SEC next Monday afternoon, July 22, with trading in the products expected to begin the next day, according to the industry sources, who spoke on background due to the confidentiality of the discussion with the SEC.

In trading late Monday afternoon, ether changed hands at $3,433.07, up 7.1% on the day and giving the cryptocurrency a 14.4% gain for the last week.

Most of the firms launched spot ETFs in January, the culmination of a decade-long tussle with the SEC which had rejected the products due to market manipulation concerns. The agency was forced to approve the ETFs, warning that the products were highly risky, after losing a court challenge brought by digital asset manager Grayscale Investments.

The launch was one of the most successful in the ETF market's history, with the nine new products drawing some $6.6 billion in assets in their first three weeks of trading, Morningstar Direct data showed. As of the end of June, the ETFs had attracted a net $33.1 billion in inflows.