Radrizzani has been in talks with Sampdoria about taking charge of the club in the coming months.
The Italian club have been relegated to Serie B and are facing massive financial problems off the pitch as well.
The Leeds chairman has made a detailed proposal with sporting and financial plans for the Italian club.
And according to French sports daily L’Equipe, his bid is set to get further strength as the PSG owners have also joined the effort.
Qatar Sports Investments (QSI) have been looking to invest in other clubs across Europe and see an opportunity in Sampdoria.
Their financial backing is likely to put Radrizzani in pole position to buy Sampdoria in the coming days and weeks.
QSI only want to be minority partners with Radrizzani left in charge of decision-making at Sampdoria if the takeover bid is successful.
There are suggestions that the Qataris could extend the partnership by investing in Leeds, but only in the longer term.