Gamco Investors Inc, the asset manager headed by Mario Gabelli, said on Tuesday it plans to adopt Eaton Vance Corp's new breed of active exchange-traded funds that can keep their holdings under wraps for months at a time.

For Gamco, the adoption of Eaton Vance's new exchange-traded managed funds (ETMF) structure to launch its own such funds marks the firm's first foray into the fast-growing $2 trillion U.S. exchange-traded products market.

Eaton Vance last year became the first firm to gain approval from the U.S. Securities and Exchange Commission to introduce so-called "non-transparent" active ETFs, which do not have to disclose their holdings on a daily basis, as is required by traditional active ETFs.

The need to disclose fund holdings on a daily basis has kept many active managers out of the ETF space for concerns over revealing a manager's winning investment strategy, on which active funds' reputations are often based.

Gabelli joins American Beacon Advisors Inc, which last month said it plans to license Eaton Vance's new ETMF product.

Gabelli said it is preparing to file an application with the SEC to seek permission to offer NextShares, the name for the new ETMF products that Eaton Vance has branded through its subsidiary, Navigate Fund Solutions LLC.

Rye, New York-based Gamco had $46.9 billion in assets under management as of the end of September.