Berlusconi, 76, a politician and media magnate, will provide Lario, 56, with $47.5 million per year but will keep possession of his villa outside Milan and his business empire, the newspaper Corriere della Sera said Friday.
Lario filed for divorce in 2009, claiming her husband was "frequenting minors," the Italian news agency ANSA reported.
They were married in 1990 and are legally separated.
The divorce arrangement was filed on Christmas Day, the BBC reported.
In March, Forbes magazine estimated Berlusconi's wealth at nearly $6 billion.