(Reuters) - BlackRock Inc. ( BLK ) on Wednesday filed an application with the U.S. Securities & Exchange Commission seeking approval to create exchange-traded fund classes for its mutual funds.

The asset management giant is the latest and by far the largest among more than 30 money managers that have made similar requests since a patent on the ETF share class structure held by Vanguard expired in May 2023.

The SEC does not have a deadline to rule on those applications, and the agency so far has only allowed Vanguard to offer both exchange-traded shares and traditional units within the same mutual fund.

Cboe Global Markets ( CBOE ) is hoping to push the SEC into ruling on the question, by seeking approval for a rule change that would permit it to list and trade ETF share classes. Regulators must respond to such rule-change requests within 240 days, which would fall toward the end of 2024.

Dimensional Fund Advisors, one of the first funds to file for permission to offer its existing mutual funds in an ETF format last year, said it has so far received letters of support from several hundred financial advisers who collectively manage $3 trillion in investor assets.