The company said Clark would join forces with another new addition, Lars Thunell, the former chief of the International Finance Corporation, to advise Blackstone on its energy investments.
The announcement comes on the heels of another high-ranking national security official, former CIA Director David Petraeus, heading to KKR Global Institute, the public policy arm of an investment firm.
Fisterra aims to finance, construct and manage large-scale independent power projects in Europe, the Middle East and South America that utilize both renewable and more traditional energy sources.
Blackstone oversees more than $218 billion in assets, making it one of the largest alternative asset managers in the world. It invests billions of equity into the energy and power sector.
The ex-NATO commander has worked on energy issues since his retirement in 2000. Following a failed presidential bid in 2003, he formed his own consulting firm, Wesley K. Clark & Associates, in 2004, advising clients in national security, energy and finance.
Clark calls himself a “progressive leader in pursuing energy solutions.” Since entering the private sector, he has been on several corporate boards, including terms on BNK Petroleum and Growth Energy, an ethanol energy lobby group.
Thunell, who is also a Swedish businessman, said, “Fisterra has the right team and experience to develop affordable, safe and reliable power projects around the world,” in a statement.
Barriuso called the two men “perfect compliments” to the senior team at the new venture.
“[They] will be invaluable as we build Fisterra into a premier global power development company,” he said.