Canada reiterated its support for the meeting, but also sounded a note of caution, suggesting the world should not act rashly.
Ban's offer was made on the sidelines of a Quebec City summit of more than 50 French-speaking nations that has been overshadowed by the global financial turbulence. Sarkozy, Canadian Prime Minister Stephen Harper and others attended.
Sarkozy later met U.S. President George W. Bush at the presidential Camp David retreat to discuss where to hold the summit, whom to invite and what it should accomplish.
Ban offered to host the summit in a public letter to Sarkozy after a bilateral meeting with him.
"We both agree that there is no time to lose and, therefore, I fully subscribe to your idea of convening such a forum in early December at the latest," Ban wrote.
"In that respect, I am pleased to offer the facilities of the United Nations Secretariat in New York."
Ban affirmed his strong support for what he described as an "expanded, emergency" summit of the Group of Eight leading industrialized nations.
French Prime Minister Francois Fillon said on Saturday night in a speech in Quebec that all the Francophone countries back the idea of a financial summit.
Sarkozy has said the world needs to "refound," or overhaul, capitalism so that it rewards entrepreneurs and not speculators, and Harper said on Friday that the current financial infrastructure was not doing its job.
However, the Canadian team did not want to go as far as Sarkozy.
"We haven't gone as far as France and said that we are rethinking capitalism," Canadian Transport Minister Lawrence Cannon told reporters on Saturday.
"We have indicated in Canada we have extremely good tools at our disposal to be able to monitor the banking system."
"Such a format will allow us to more effectively act upon a crisis, which requires a global solution through cohesive international partnership."
Harper spokesman Dimitri Soudas also sounded a note of caution.
"Canada, of course, recognizes that the present international situation remains very delicate and our collective action should be taken with precaution and coordinated in a way so that the crisis does not widen," he said.
"It's also important to make sure that our actions don't make the situation worse. Our actions must be robust, but also prudent, and it's important not to cause permanent damage to the international financial system," he added.