Former Italian premier Silvio Berlusconi has revealed he is engaged to a woman almost 50 years his junior, and says that "finally I feel less alone."

The 76-year-old media baron said on Sunday his engagement to 28-year-old Francesca Pascale part of a support group called "Silvio, we miss you" is "official".

Berlusconi's second wife left him in 2008, citing alleged dalliances with young women. He is now on trial on charges of having sex with an underage woman and using his office to cover it up.

Newspapers described Berlusconi's appearance on Canale 5 one of his television networks as attempt to boost falling approval rates ahead of an election early next year.