The Portuguese side are keen to bring in Leto as a replacement for Angel di Maria, who is expected to leave the club this summer.
Leto’s contract with Panathinaikos is set to expire in the summer of 2014.
“I know there is some interest and that a document is likely to have arrived at our headquarters for a first approach, but no official offer from Benfica for Leto has arrived,” Panathinaikos vice-president Giannis Venkis told A BOLA.
“Negotiations are likely to start on Monday as €10 million euros are seductive.”
