In Italy, Berlusconi, the prime minister, has used an interview on one of his own television channels to accuse Murdoch of mounting a personal attack through a newspaper owned by the News Corporation, his global media empire.

The articles and editorials in question, in The Times of London, examined the relationship between Berlusconi, 72, and an 18-year-old model, Noemi Letizia. Murdoch, appearing on a television channel in New York owned by the News Corporation, discounted Berlusconi’s claims of a personal attack, calling them nonsense and saying that other newspapers, not owned by his company, have been even more critical. On that level, the dispute may seem as farcical as the antics on an Italian variety show. But on another, the rivalry between the men is serious, and is heating up.

Berlusconi is “fearing what Murdoch could do in Italy,” said Fabrizio Perretti, a professor at Bocconi University in Milan who studies the Italian media industry. “And that’s why he accused Murdoch, even if he isn’t really to blame.”

News Corporation owns Sky Italia, a satellite broadcaster that has dominated the pay-television business in Italy since the company was created in 2003. Berlusconi’s family holding company, Fininvest, is trying to challenge Sky’s hold on pay TV. Despite Sky’s strong position — with more then 4.7 million subscribers, it reaches about a quarter of Italian households — media analysts say changes in the national market could create an opening for Mediaset, a company controlled by Fininvest.

“The competition is going to reach a new level of intensity in the second half of this year,” an analyst at Screen Digest in London, Tim Westcott, said.

Italian television is unusual because the country has virtually no cable service, and new services that send programming over broadband Internet connections — a technology that is growing rapidly elsewhere in Europe — have been slow to catch on. Not long after Sky Italia was created, Mediaset started a pay-TV service, using encoded signals broadcast digitally, over the regular airwaves. With set-top boxes and prepaid cards, like those that many Italians use to pay for cellphone services, viewers can unscramble the signals, which include broadcasts of top soccer matches.