FACTBOX: Italy's Silvio Berlusconi, riding back to power?

(Reuters) - Italy's opposition leader Silvio Berlusconi said he was "100 percent" sure he would win a parliamentary election at the weekend.

The election was called after Romano Prodi's centre-left government imploded earlier this year.

Italian law bans opinion polls from two weeks before the April 13-14 vote, but the last ones published showed Berlusconi, known as Il Cavaliere, "The Knight", 5-9 percentage points ahead of his opponent, former Rome mayor Walter Veltroni.

Following are some key facts about Berlusconi:

* With a gleaming smile and year-round tan, Berlusconi, born in Milan in September 1936, entered politics in January 1994 promoting a "you can be rich like me" message.

* He was elected prime minister and took office in May but survived just eight months and languished for more than six years in opposition.

* Swept to power by a landslide victory in 2001, Berlusconi promised to revolutionize hidebound Italy. But change came slower than many hoped for and the economy barely grew during his five years in power.

* Berlusconi denied any failings, insisting that his government fulfilled its domestic reform program.

* Berlusconi lost the April 2006 general election by the narrowest margin in Italian history, almost pulling off a dramatic comeback after opinion polls put him way behind until the last days of campaigning.

BERLUSCONI BUSINESS:

* Berlusconi made his fortune during a property boom in Milan in the 1960s. He then moved into television and his family now owns the country's leading private TV network. His interests also include top Italian soccer club AC Milan.

* Controversially he has kept control of his huge media empire, laying himself open to accusations of a conflict between his political and business interests and also vulnerable to numerous corruption investigations into him and his companies.

* Berlusconi went on trial again in late 2006 charged with fraud at broadcaster Mediaset, which his family controls.

* Combining the smooth talk of the business tycoon with a common touch, Berlusconi is one of Italy's richest men whose fortune Forbes put at $12 billion.

A HEALTH PROBLEM:

* It wasn't all smooth sailing, however, as in late 2006 he was admitted to hospital with a minor heart problem after fainting. He underwent successful heart surgery in a U.S. hospital in January 2007.

* In November 2007, Berlusconi broke up his Forza Italia (Go Italy!) party, as well as the "House of Freedoms" alliance with Catholics, northern separatists and post-Fascists. He has called his new group the "Party of Freedom" or "People of Freedom" party, which he hopes will bring him back to power.

(Writing by Gavin Jones and David Cutler, London Editorial Reference Unit)