The European Union on Saturday raised an offer by rich nations to help poor countries worst hit by climate change to three hundred billion dollars a year in a bid to salvage talks that the developing world warned were on the brink of collapse.

Negotiators worked through the night in a windowless sports stadium in the Caspian Sea city of Baku in a search for compromise as the two-week UN climate talks dragged into an extra day.

In a year set to be the hottest ever recorded, developing nations bearing the brunt of rising drought and disasters flatly rejected Friday an initial offer of two hundred and fifty billion dollars per year by 2035.