"Mr Hollande, who is the Socialist Party's challenger to President Nicolas Sarkozy at next year's elections, said the agreement was not the right solution for the European Union.
He said he wanted greater powers for the European Central Bank (ECB) and for member states to issue joint eurobonds.
Germany is opposed to such measures.
Speaking to RTL radio, Mr Hollande said: "This accord is not the right answer, nor does it have the urgency.
"If I am elected president, I will negotiate, renegotiate this deal to include what is missing today."
Polling organisations currently predict that Mr Hollande would beat Mr Sarkozy in the second round of voting."
If Hollande wins and delivers on his promise, this means the dissolution of the Franco-German unity, no?
Wojtek