Swiss International Air Lines and its parent Lufthansa Group have agreed with synthetic fuel group Synhelion to use its solar aviation fuel, the Swiss airline said on Tuesday.

"This will make SWISS the first airline in the world to use 'sun-to-liquid' fuel," it said in a statement.

The process devised by Synhelion, a spinoff from the Swiss Institute of Technology, uses concentrated sunlight to produce carbon-neutral kerosene, it said.

"Our next-generation carbon-neutral solar kerosene is an economically and ecologically viable substitute for fossil fuels," Synhelion co-founder and CEO Philipp Furler said.

"The commitment of SWISS and the Lufthansa Group underlines the aviation sector's keen interest in our solar fuel."

Synhelion will build the world's first facility for the industrial production of solar fuel in Germany this year, the statement said. SWISS is set to become the first customer for the solar kerosene in 2023.

The deal calls for SWISS and the Lufthansa Group to support development of Synhelion's planned commercial fuel production facility in Spain as well.