United Airlines announced today a new purchase agreement with sustainable aviation fuel and renewable diesel producer Neste for up to 52.5 million gallons of sustainable aviation fuel (SAF) over the next three years to power flights out of Amsterdam’s Schiphol Airport.

The deal marks the first agreement signed by a U.S. airline to purchase SAF overseas, and is the Neste’s largest SAF agreement to date with a passenger airline.

SAF is seen as one of the key tools to help decarbonize the aviation industry, which currently accounts for 2-3% of global greenhouse gas (GHG) emissions. SAF is generally produced from sustainable resources, like waste oils and agricultural residues. Neste said that its SAF reduces lifecycle GHG emissions by up to 80%, and the company expects to produce 515 million gallons of the fuel per year by the end of 2023.

Under the new agreement, Neste will provide United with 2.5 million gallons of SAF in Amsterdam in the first year, and United will have the right to buy up to 20 million gallons in the second year, and up to 30 million gallons in the third year, at Amsterdam or other locations.

Thorsten Lange, Executive Vice President, Renewable Aviation at Neste said:

“We’re excited to be partnering with United in this milestone purchase agreement and make our SAF available to United, also an industry leader in SAF investments. Our global, fast-growing SAF production and supply chain supports airlines and their customers in reducing greenhouse gas emissions. Neste is committed to helping aviation transition to a more sustainable future, and we look forward to expanding our cooperation with United.”

United Airlines has committed to fully reduce greenhouse gas emissions by 2050 without relying on carbon offsets. The agreement marks the latest in a series of SAF-focused initiatives for the company, including the launch last year of the Eco-Skies Alliance, a program aimed at enabling corporate customers the opportunity to reduce the environmental impact of travel beyond purchasing offsets, by paying the additional cost of SAF and it is the latest in a series of actions by the US carrier. In December, United completed its first passenger flight with a 100% sustainable aviation fuel-powered engine.

Lauren Riley, United’s Chief Sustainability Officer, said:

“The demand from our customers to limit their emissions from flying is growing exponentially, and this agreement means that United customers flying from Amsterdam, and potentially more airports, will be partners in our sustainability efforts.”