With the registration at the SIAE of an inedited work we do not make a deposit of a patent application, but we simply make a deposit of a creation already protected as is according to the law on copyright, for the purpose of having a determined date testifying the work creation by certain authors at a certain historic moment. Therefore, in this specific case, it is not correct talking of ownership at 50% of the patent right, as we have two co-authors. Having said this, we need to add that on the created software two rights are recognised to the authors: a right of financial exploitation of the finding and a moral right to be recognised as the author. The first one is alienable and can be given to anybody, the second one remains owned, for ever, by the author, therefore, should others buy the created work, they must always specify who was the author.
In any case, the co-author can always give his shares of ownership of the software to third parties without forming any company or further developing the project, on condition though, that it is a finished work and can be protected by the law on copyright. If this is the case, the problem can be resolved simply by making a private agreement with the person interested in buying it, properly describing what is to be sold, so that the counterpart will know exactly what he is buying and cannot later complain or ask for a refund of whatever paid as the item of the contract does not comply to what promised. As it is an inedited work, the deposit at the SIAE will still be in the name of the actual creator but, in fact, the economic rights are sold and the original owner cannot claim anything in case of a commercial success. Nevertheless it is advisable, as there are two authors, to get a written renunciation by the other co-author upon the buying of his share, so that the whole operation will be without any risks.