Agricole will pay $9.97 billion for regional savings banks Cariparma and Banca Popolare and the branches of Banca Intesa.
The deal had initially been announced last October but was pending approval from the European Commission and the Bank of Italy, that decided that the deal breached antitrust laws.
In order for the deal to go through Intesa had to sell some of its retail branches, that will now form the largest bank in Italy with former rival Sanpaolo.
Commenting on these developments, Rene Carron, Credit Agricole chairman, said: "Acquiring Cariparma and FriulAdria enables us to operate a quality network and expand in Italy. Finalising the deal announced last October is also a decisive step in Credit Agricole's international expansion."
Agricole will now own 600 retail bank branches in Italy and gives it a two to three per cent share of the Italian market.