FILE PHOTO: The logo of French postal service company La Poste is seen on a post office in Paris, France, March 28, 2018. REUTERS/Charles Platiau/File Photo

PARIS (Reuters) - France's La Poste is planning to buy the stake in insurer CNP Assurances CNPP.PA held by state-owned investment fund Caisse des Depots though the details of the deal are not yet finalised, a source close to the mail company told Reuters on Thursday.

La Caisse des Depots et Consignations, or CDC, would hand over its 41 percent stake in CNP Assurances in exchange for a stake in La Poste, which already owns a bank, the source said, confirming an earlier report by Les Echos newspaper.

La Poste would then merge its bank, La Banque Postale, with CNP Assurances to expand the range of services it provides.

The French government, which owns both CDC and La Poste, wants to build up a state-owned company that would provide both banking and insurance services in the country’s rural areas which are often neglected by private rivals.

“The idea is to go that way,” the source said.

Details of the operation such as the size of the stake CDC would hold in La Poste are still being discussed, he added.

La Poste already holds an 18 percent stake in CNP Assurances and has a shareholders’ agreement with French private bank BPCE, which also holds 18 percent.

Les Echos said top officials at CDC would will discuss the issue next week.

Officials with CNP Assurances and CDC could not be reached for comment. A spokesperson with La Poste declined to comment.