GE Energy Financial Services backs methane start-up Ciris Energy.

Ciris Energy, a US-based company that converts coal to methane, has raised $23.9m of its planned $39.7m round from five investors, including GE Energy Financial Services, a unit of New York-listed industrial conglomerate General Electric.

Venture capital firm Khosla Ventures is also participating as a new investor, according to the company, alongside peers Braemar Energy Ventures and Rho Ventures.

Investment bank Lazard Freres is helping Ciris, which collected $4m earlier last year to test its process, raise the latest round,…