Neymar is reportedly a major target for PSG, who are believed to be willing to meet his €222 million release clause .
Blanc, who was in charge at PSG from 2013-16, believes signing the Brazil star would take his former club to another level, but warned it was no guarantee of success in Europe.
"Paris want to become a great European club. It is a club that has incredible economic potential," he told Italian media, via RMC Sport .
"With a player of Neymar's level, PSG could become this great club in Europe in the future.
"The Champions League with him or with other players takes time. It is not a competition you win only by spending millions. Football doesn't work like that. A club needs stability.
"PSG grew very quickly, it is a club that has become important and will one day win the Champions League."
Neymar showed again what he is capable of by scoring a brilliant brace in a 2-1 win for Barca over Juventus at the International Champions Cup on Saturday.