Clean energy company Rentech Inc. on Tuesday said that General Wesley K. Clark, a former NATO supreme allied commander with a background in energy issues, is joining its board of directors.

Clark, who retired in 2000, rose to the rank of four-star general in the U.S. Army. In addition to the NATO post, he also held the position of commander in chief of the U.S.-European Command. He briefly considered a run for U.S. president in 2004.

He now runs a strategic consulting firm, Wesley K. Clark & Associates, and is chairman of investment bank Rodman & Renshaw. He has focused on energy issues, including serving as chairman of Clean Terra, a firm he co-founded that assists scalable clean energy and fuel projects and furthering clean-technology public policy. He also serves on the energy and climate change advisory board of the Clinton Global Initiative.

The Rentech-SilvaGas biomass gasification process converts plant material into ultra-clean synthetic jet and diesel fuels, specialty waxes and chemicals.

“General Clark has extensive international, investment banking and entrepreneurial experience and a strong commitment to securing domestic alternative sources of energy,” Chief Executive D. Hunt Ramsbottom said in a statement.

Shares were down 1 cent, or less than 1 percent, to $1.25 in midday trading on the New York Alternet.