"Yes, thanks, of course I meant POTUS," the 80-year-old newcomer to Twitter replied minutes later. "Somehow iPad changed my spelling. I should have checked. Sorry."

Others quickly joined in, asking Murdoch what he had against our Telco.

The gaffe was immediately noticed by Australians, with ABC boss Mark Scott pointing out Murdoch would have caused: "Cheers at Telstra, confusion at Optus - and amusement from the Potus team."

What Murdoch had intended to write - and who he had intended to target - was POTUS, a common nickname for Barack Obama, the President Of The United States.

The mogul has been using his Twitter account to attack President Obama and Google recently over Google's lobbying against legislation in the US congress that would hinder Internet piracy.

Mr Murdoch is a very recent and game entrant to the social networking site, but this is not his first misfire.

Only two days after he opened his account on December 31 he became the Twittersphere's flak magnet number one after tweeting the British people holiday far too much for a "broke country". On holiday himself at the time, he deleted the message almost immediately but his followers, already in their tens of thousands, had already retweeted it.

It was soon made clear by the elderly mogul his initial forays had made his familiars a trifle jittery.

Mr Murdoch tweeted "I'm getting killed for fooling around here and friends frightened what I may really say!" A couple of days later a wrongly verified account, @wendi--deng, which had purported to be that of his wife, Wendi Deng Murdoch, was exposed as a hoax. Suspicions were raised when "Deng" had sent tweets telling Mr Murdoch off, and apparently flirting with Ricky Gervais.