French energy group EDF and Italian counterpart Enel said Friday they had reached agreement to enable Enel to take part in the development of a third generation nuclear reactor in France.

The accord, signed during a French-Italian summit here, calls for Enel to take a 12.5 percent stake in an ongoing project to build the reactor in Flamanville in northern France.

Enel in addition would have an option to participate in the construction of five additional third generation European Pressurised Reactors to be built by EDF, Electricite de France.

The agreement will also enable Enel to have a 30-40 percent interest in two combined cycle reactors that EDF will put into service between 2010 and 2012.

In exchange, EDF will have access to Enel's traditional and nuclear production capacity at an equivalent level in the framework of Enel's European projects.

A partnership letter of intent was signed by the two companies in 2005 but a final deal was held up by political differences, with EDF fearing that its operations in Italy could be hampered.