Struggling Italian football club Unione Calcio Sampdoria SpA is searching for new financial backers after some prospective investors cooled on the deal.

Sampdoria’s owners, Andrea Radrizzani’s Aser Ventures and Gestio Capital, are pressing ahead with the search after talks with parties including Qatari Sports Investments — which controls top French football team Paris Saint-Germain — and the Reuben Brothers failed to result in an offer, according to people familiar with the matter, who asked not to be identified because the talks are private.