A potential deal would value Eugin at around 500 million euros ($528.55 million), the newspaper said.

KKR would buy the clinics with a Spanish partner, it added.

The U.S. fund already owns assets in the industry in the country, Cinco Dias reported.

KKR, Fresenius and Eugin did not immediately respond to messages seeking comment.

($1 = 0.9460 euros)

(Reporting by Inti Landauro, Editing by Louise Heavens)