PARIS: General Electric and Safran signed Monday a deal extending their cooperation as they set their sights on next-generation jet engines that will help airlines reduce costs and pollution.

The US and French engineering giants have been cooperating in the sector for nearly half a century, and the LEAP engines developed by their joint venture CFM power some the latest generation Airbus and Boeing aircraft.

But with the air sector pledging to cut its carbon emissions in half by 2050 from their level in 2005, airlines are going to need new technologies.

The groups announced that CFM would push forward with its RISE (Revolutionary Innovation for Sustainable Engines) programme that aims to develop by the mid-2030s engines that cut fuel use and emissions by 20 percent.

One technology that will be pursued is open fan architecture. The fans in current jet engines are enclosed. But opening them up, like on a turboprop, could help improve performance.

"When we talk about a 20-percent reduction in fuel burn, that's a reduction relative to today's" jet fuel, GE's chief executive John Slattery said during an online news conference.

If a sustainable jet fuel were used "that would reduce CO2 by 80 percent and if it was hydrogen, which is kind of the nirvana, that would reduce CO2 emissions by 100 percent," he said.

Airlines are already experimenting with jet fuels made from renewable sources and aircraft manufacturer Airbus is looking at making a plane powered by hydrogen by 2035.