Asset manager Legg Mason finally made a move to stake a claim in the exchange-traded fund space.

Rumors had Baltimore-based Legg Mason eyeing actively managed ETFs since last fall. This week the company filed papers with the SEC that would allow it to launch just such a family of ETFs.

The filing laid the groundwork for actively managed vehicles ranging from domestic and/or global equities to fixed-income asset classes, though the company didn’t specify which funds it would launch.

Most active ETFs have yet to show sizable asset inflows. Still, companies such as T. Rowe Price, Pimco, Goldman Sachs and Charles Schwab are entering or thinking about entering the actively managed ETF space.

There are plenty of arguments why active ETFs have not caught on with investors, as you can read in Matt Hougan’s recent blog about the trend.

Legg Mason’s move comes days after RiverPark Advisors made a similar SEC filing seeking exemptive relief to launch active ETFs. RiverPark already subadvises four active ETFs for Grail Advisors, all of which have gathered less than $5 million in assets.

Exemptive-relief filings grant exemptions to parts of the Investment Act of 1940, and represent the first hurdle fund companies must clear to issue ETFs.