"I've given myself a birthday gift, I've signed Benitez," De Laurentiis said in an interview with Mediaset television in London.
"I'll make it official in the next few days as Benitez needs to end things with Chelsea. He'll have a two-year contract, no longer. We need to get to know each other first, then we'll see."
Spaniard Benitez will replace Walter Mazzari, who left the club after their 2-1 loss at AS Roma in their last game of the season on Sunday.
Mazzari took them to second place in Serie A and re-established them as a force in Italian football. They also won the Italian Cup last season.
Local media reports said there was a meeting in Rome on Thursday between representatives of Napoli and Benitez during which an agreement was reached on a two-year contract worth 3.5 million euros per season.
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