Zurich Insurance Group AG, Switzerland’s biggest insurer, said it will spend as much as $1 billion on green bonds, making it the largest investor in such clean-power securities.

The insurer has appointed BlackRock Inc., the world’s biggest money manager, to select green bonds issued by the World Bank and other development institutions, the Zurich-based company said in an e-mailed statement today.

Investors are snapping up bonds to finance the global expansion of clean energy, promoted by governments from the U.S. to China to tackle climate change. The debt, issued by development banks or project sponsors themselves, offers investors an alternative to volatile equities.

“Green bonds are a good fit with Zurich’s overall investment strategy as well as its impact investing aspirations, targeted to support sustainable development and resilient communities,” Zurich Insurance Chief Investment Officer Cecilia Reyes said in the statement. “It’s an opportunity to invest both with impact and at a return fully compensating for the risk.”

–Editors: Simone Meier, Jon Menon