"MONTREAL/WASHINGTON -- Europe and the United States tried to bridge differences over emissions standards for aircraft on Sunday as global aviation leaders prepared to adopt new rules that could affect Boeing Co and Airbus Group's production of the largest jetliners and freighters.

Proposals being debated in Montreal by the International Civil Aviation Organization (ICAO), the United Nations' aviation agency, would force makers of the world's largest passenger jets to upgrade or stop producing certain models as early as 2023, according to sources close to the negotiations and documents seen by Reuters.

U.S. and European negotiators are trying to come up with the world's first carbon dioxide emissions standards for aircraft as part of the industry's contribution to efforts to combat climate change."

Allison Lampert and Valerie Volcovici report for Reuters February 7, 2016. [2]