The Italian Prime Minister already controls two dailies and a news weekly; his company, Mediaset, owns the three main commercial TV channels, while as Prime Minister he also has, in effect, control over the output of RAI, the state broadcaster.
Rumours that Mr Berlusconi was stalking the Milanese daily in advance of next year's general election have been doing the rounds for months.
When it was revealed earlier in the year that a wealthy Roman estate agent, Stefano Ricucci, had acquired more shares in the company that controls the newspaper than any other single shareholder, alarm bells began to ring.
June saw Mr Berlusconi's first attempt to distance himself from Mr Ricucci's ambitions. "I guarantee on my honour and my word that there is no interest in RCS [the group that controls the newspaper] on the part of my group," he said.
But in the same speech, the media billionaire also spoke of "this unacceptable hostility" towards Mr Ricucci's manoeuvres.
This indication that, at the very least, Mr Berlusconi was less than neutral regarding the newspaper's future came back to haunt him this week when Sergio Romano, a retired diplomat and a columnist on the paper, warned of "the shadow of the Prime Minister".
Now Mr Ricucci holds 19 per cent of the firm's shares, and the newspaper's share price has soared on rumours of a takeover bid.
This week the mutterings about Berlusconi turned to roars when it emerged that a number of businessmen close to him are also involved in Mr Ricucci's manoeuvres, including a financier, Ubaldo Livolsi, who sits on the board of Berlusconi's finance company, Fininvest, and rescued Mr Berlusconi from disaster during the 1990s.
Yesterday, in a statement, Mr Berlusconi described "my presumed but totally inexistent participation in a takeover of RCS" as "a castle of fantasies and lies".
Of the storm of rumours in the newspapers in recent days, he said, "One asks oneself, who is organising all this, and why?" But the denial is unlikely to silence the rumour mill.
Enrico Letta, an MEP and former minister in the centrist Margherita party, said: "Ever since Berlusconi went into politics he has continually tried to control or purchase Corriere.
In this parliament his attempts have become frenzied: he has tried it with every ally possible and imaginable." The reason adduced for Mr Berlusconi's "obsession" is that in the Italian newspaper world, Corriere della Sera is in a class of its own, for circulation - about 880,000 - and influence.
Of the two dailies he currently controls, Il Giornale has degenerated into a government mouthpiece, while Il Foglio is a conservative talking shop.