"There will be a decision on financial transaction taxes before the end of January as far as France is concerned," Henri Guaino, a special adviser to Sarkozy, told BFMTV news channel.
"France will set the example on this issue," he said.
Asked if Paris was prepared to put in place transaction taxes even if Germany did not do so, Guaino said: "It is better if Germany is involved."
"We will keep discussing it in the coming days and weeks, but France is ready to take the lead on this issue... and hopes it can bring others along," he said.
When asked about the French position on a so-called Tobin tax, German government spokesman Steffen Seibert told reporters: "The German position has been the same for a long time. We would like to see a global financial transaction tax but that is not possible at the present time. The German government would thus aim to introduce the financial transaction tax within the EU."
He noted that Finance Minister Wolfgang Schäuble said in December that Germany and France wanted to size up the situation within the EU in the first weeks or months of this year by assessing how much support such a tax had.
French minister for European affairs Jean Leonetti said Wednesday that a European financial transaction tax would be in place by the end of year, apparently moving up the programme.
"This is on the programme for the next European summit (on January 30). Nicolas Sarkozy and (German Chancellor) Angela Merkel have decided on this and it will be put in place before the end of 2012," he said.
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Last month, French Finance Minister Francois Baroin said France and Germany were to present their financial transactions tax proposal on January 23 with the hope it will be implemented across Europe in 2013.
Britain is opposed to transaction taxes being implemented across the 27-member European Union.