It is not uncommon for an inventor to file both a French and a European patent application for the protection of a single invention. There arises the question of the separate use of those two patents. Thus, the independent assignment of one of the two patents is naturally prohibited in all cases, as it would result in the coexistence of two distinct and competing property rights in France on the same invention.
Indeed, article L. 614-14 of the Code of Intellectual Property provides that: “Where a French patent application or a French patent and a European patent application or a European patent have the same filing or priority date, cover the same invention and belong to the same inventor or to his successor in title, those parts which are common may not be transferred, pledged, mortgaged or their exploitation rights assigned independently of each other or these transactions would be null and void”.
However, in some cases, the nullity incurred is absolute, and may be claimed by everyone, whereas in other cases, the nullity is relative and may be claimed only by the contracting parties.
Therefore, with regard to patent licensing, according to a certain legal doctrine the nullity incurred should be relative. Indeed, these contracts do not deprive the inventor of his/her ownership rights, and only the licensees who own competing rights on the same invention are at risk of prejudice.
However, in 2008, the Tribunal de Grande Instance of Paris rejected the above analysis by a literal application of article L.614-14 of the Code of Civil Proceeding (TGI Paris, 20 février 2008, RG 2006/14907). It was stated, in very clear terms, that “the legislator intended to protect third parties as well as contracting parties from the possibility of a coexistence on the same invention and on the same territory, after the definite grant of titles”, without operating a distinction “between the contracts which transfer definitely the ownership of the property title and those which operate a transfer of rights to temporary use”.
In another court case, the Cour de cassation seems to nuance the above analysis, by means of a formulation that could constitute a landmark reference. The Court states that where a French patent application or a French patent and a European patent application or a European patent have the same priority dates, cover the same invention and belong to the same inventor, “the exploitation rights of the common parts, may not be assigned independently of each other” (Cass.Com, 16 décembre 2014, n°13- 23986).
Furthermore, the Cour de cassation states that the Court of appeal should not have totally rejected the argument of the appellant companies claiming the nullity of the license, as the company licensee of patents for France, did not hold, according to the terms of its contract, an exclusive right to use the French patent applications. The wording seems to suggest, by a reading a contrario, that if a territorial exclusivity had been arranged between the different license contracts (the license of the French patent being exclusive, and the license for the European patent explicitly excluding France), the French Licensee could have, on the contrary, acted legitimately, in the absence of absolute nullity of his/her contract. This pragmatic approach needs to be welcomed, even though the articulation between the different geographic scopes may, within a global economy, prove to be complex.