The U.S. Securities and Exchange Commission has approved four asset managers' plans to roll out exchange-traded funds that would disclose their holdings once in a quarter, as opposed to the daily releases conventional ETFs make, Bloomberg News reported.

T. Rowe Price Group Inc., Natixis, Fidelity Investments and Blue Tractor join Precidian Investments LLC in having their respective offerings greenlighted. The SEC tentatively signed off on T. Rowe, Natixis, Fidelity and Blue Tractor's requests in November. The regulator granted exemptive relief for Precidian's ActiveShares exchange-traded fund structure earlier in the year.

The newly approved models will use proxy baskets, allowing market makers to price their funds without revealing the whole portfolios.

Active managers have been reluctant to start their own ETFs for fear that their strategies would be revealed because of the required disclosures, but the companies now face a new challenge as they would need to persuade clients that their offerings are better than transparent ETFs and their competitors' structures, the news outlet added.

The actively managed, non-transparent offerings will have a difficult time gaining momentum in the ETF market due to lack of "natural demand," Bloomberg noted, citing Bloomberg Intelligence ETF analyst Eric Balchunas.