Former Ameritrade chief Thomas Lewis was named Tuesday to head Green Exchange Holdings LLC, an emissions-focused market backed by CME Group Inc. (CME).

The appointment comes as the nascent New York market seeks regulatory approval from the Commodity Futures Trading Commission and the U.K. Financial Services Authority ahead of a broader rollout.

It also marked another step for CME into a developing asset class that could become one of the largest derivatives markets, as governments move to mandate trading of greenhouse gas emissions to curb pollution.

"Green Exchange Holdings has an opportunity to shape the future of trading environmental products by creating a globally integrated marketplace," Lewis said in a statement. "It will enable market participants to gain exposure to environmental markets and manage their risk through a diversified product slate."

The Green Exchange came onto the scene in December 2007, backed by a consortium of Wall Street banks, the New York Mercantile Exchange and the emissions brokerage Evolution Markets Inc., where Lewis served as a director.

Chicago-based CME, the world's biggest futures exchange operator, acquired its stake in the Green Exchange in 2008 via the purchase of Nymex.

The Green Exchange's slate of products, currently listed for trading and clearing by Nymex, cover futures and options on European Union Allowances, carbon allowances tied to the Regional Greenhouse Gas Initiative, and other greenhouse gas markets.

Despite its powerful backers, trading activity on the Green Exchange platform has yet to take off, partially due to the uncertainty created by the CME-Nymex merger.

However, CME Group senior management has expressed support for the venture in recent months and introduced new emissions- and carbon-focused products at Nymex, which are eventually slated to transfer to the Green Exchange.

In both U.S. and European carbon markets, the Green Exchange will play catch-up to Climate Exchange PLC (CLE.LN), which operates the dominant carbon markets on both sides of the Atlantic.

CME rival IntercontinentalExchange Inc. (ICE) in June took a minority stake in Climate Exchange, which already used ICE's trading platform.

Besides Ameritrade, Lewis also served as chief executive of Automated Power Exchange Inc. and was an executive in residence at John Hopkins University, where he focused on environmental finance.

-By Jacob Bunge, Dow Jones Newswires; 312-750 4117; jacob.bunge@dowjones.com