"Talks are already at a very advanced stage," the newspaper quoted a source close to the negotiations as saying.
The head of Fiat, Sergio Marchionne, had said om Tuesday that the Italian group was planning an alliance with another car maker by the end of the year.
"We're set to seal an industrial alliance, not a financial one, before the end of the year. The aim is develop our products. It won't be with an Asian partner," he had said.
The new supermini Fiat is keen developing is the 500, which will share its underpinnings with the next generation Ford Ka.
Both cars are expected to go on sale in 2007.