BRUSSELS, Dec 15 (Reuters) - European Union leaders wrapped up their last summit of 2022 with an agreement to provide 18 billion euros in financing to Ukraine next year and slap more sanctions on Russia as the EU also prepared to cap natural gas prices and prop up its industry.Poland withdrew last-minute objections to a global minimum corporate tax, unblocking a package of linked agreements that includes the loan to Ukraine, where a war has raged since Russia launched an invasion in February that Moscow refers to as a "special military operation".As Ukrainian President Volodymyr Zelenskiy predicted that the months to come would be ever harder than the war had already been on his country, German Chancellor Olaf Scholz promised more aid.With heating reduced in EU buildings as part of measures to save energy, some leaders were seen wrapped in big shawls as they gathered to discuss their response to the U.S. Inflation Reduction Act - $430 billion worth of tax breaks for green energy.The summit charged the EU Commission with making specific proposals early next year to prop up the EU's cutting-edge industries - including biotech and AI - while also preserving competition inside the bloc's cherished single market of 450 million consumers."