Unlike in the United States, where even the smallest newspapers claim to hew to the same standards of objectivity, the journalism in Mr Murdoch's global media empire runs from serious to salacious, from evenhanded to partisan. And, like many overseas news outlets, Mr Murdoch's newspapers and journalism businesses often are aligned with governments.

This has caused what many journalists consider to be the unacceptable intrusion of Mr Murdoch's corporate and political interests into his journalism and media operations.

As Mr Murdoch's unsolicited US$5 billion (S$7.6 billion) bid for Dow Jones, parent of the Wall Street Journal, has gained ground in recent days, the question becomes more urgent: What would he do to the Journal if he owned it?

The Bancroft family, which controls Dow Jones, has sought assurances that a Murdoch-owned Journal would remain editorially independent before it would support a sale.

Dow Jones' tentative deal with News Corp provides that the current managing editors of The Journal and Dow Jones Newswires, and the editorial page editor, would remain in place and would have sole authority over content and news staffing.

News Corp could not remove any of those top editors, or appoint someone new to any of those posts, without the consent of a special committee whose five original members would be chosen jointly by News Corporation and the Bancroft family.

Mr Murdoch is the face of News Corp in a way that separates it from other major media companies.

'You are working for one man, not a faceless organisation,' said Mr Roy Greenslade, a journalism professor at City University in London and a media commentator.

When sensitive stories come along, Mr Greenslade believes that even if they have not heard from Mr Murdoch directly, Mr Murdoch's editors are thinking, 'What would Rupert think?' and there is 'a self-censorship'.

Mr Murdoch treats his different products differently. He enjoys rolling up his sleeves and jumping into his tabloids, such as London's The Sun (known for its topless Page 3 girls) and the New York Post, but - at least in recent years - has tended to leave his more serious products, such as the Times of London, alone.

Mr Robert Thomson, editor of the Times, said allegations of self-censorship 'call into question the integrity of every journalist at the Times'. He said Mr Murdoch does not meddle with the Times' editorial content, and he dismissed critics who he said make such allegations without offering evidence: 'They say you don't need evidence - it's so subtle you actually can't see it in the pages of the Times.'

Mr Thomson is advising Mr Murdoch on the Dow Jones bid.

With the Times, Mr Murdoch has a written agreement not to interfere editorially; that is not the case with the tabloids. Mr Greenslade said the editors of The Sun wanted to 'ditch' Prime Minister Tony Blair but Mr Murdoch didn't, so they continued to support him.

In former Times editor Harold Evans' 1983 book Good Times, Bad Times, he quotes Mr Murdoch as saying that his promises of editorial independence for the Times 'aren't worth the paper they're written on', a statement News Corp disputes that Mr Murdoch made. Mr Evans declined a request for an interview, as did Mr Murdoch.

'In my experience, Rupert Murdoch understands that what we call quality newspapers are very different from tabloids,' said Mr Simon Jenkins, editor of the Times from 1990 to 1992 and now a columnist for the Guardian and the Sunday Times.

'He is an instinctive tabloid editor and regards his British tabloid papers as, in some sense, his,' Mr Jenkins said. 'He frequently sort of co-edits the tabloids - that's his fun.'

Mr Murdoch's News Corp is worth US$70 billion and is bigger than Disney but smaller than Time Warner.

In the United States, News Corp includes the Fox television network and Fox News Channel, the New York Post, the Twentieth Century Fox movie studio, FX cable channel, HarperCollins book publishers, pieces of the DirecTV satellite service and the National Geographic Channel, and MySpace. Overseas, Mr Murdoch has newspapers, magazines and satellite services in England, Italy, Australia and Asia.

Newspaper owners come from a grand tradition of using their presses to further their political or business aims. In past centuries, power - and an uninterrupted flow of profits - were the main reasons to own a newspaper. In the late 19th century, when the US government was but a small fraction of its modern-day size and influence, New York publishers such as William Randolph Hearst and Joseph Pulitzer essentially had their own foreign policies.

Throughout much of the 20th century, however, major US newspapers attempted to limit advocacy to the editorial pages. Editorial independence from owners and publishers has come to be high religion in newsrooms.

The British and Australian style of tabloid journalism, with which Mr Murdoch is so closely associated, tends towards the popular and sensational - and politically aligned. Even though the Australian-born Mr Murdoch became a US citizen in 1985 (to comply with US rules prohibiting foreign ownership of television stations), his brash style of journalism is as alien as his accent to many US journalists.

Mr Murdoch is politically connected in the nations where he does business and is adept at staying close to those in power, regardless of party and ideology. For example, he has supported the Australian Prime Minister, Mr John Howard, but recently told Australian television that Labor Party leader Kevin Rudd, a possible successor to Mr Howard, would make a good prime minister.

Some Murdoch watchers regard such manoeuvring as good business.

Others see something darker. 'The essence of Murdoch is that he does government propaganda on a privatised basis,' said Mr Bruce Page, author of The Murdoch Archipelago, which argues that Mr Murdoch's newspapers cozy up to political power to help his businesses, and are unlikely to criticise sitting governments.

'This rubbish might sell books, but it doesn't stand up to scrutiny,' News Corp spokesman Andrew Butcher wrote in an e-mail response. 'Our papers around the world are fierce critics of governments when appropriate.'

In 1994, Mr Murdoch removed the BBC from his Star satellite television broadcasts to China. The BBC had aired reports critical of the Chinese government. At the time, Mr Murdoch told writer William Shawcross that he cut the BBC to appease Beijing. But in a Financial Times interview recently, Mr Murdoch said he did it to save money.

'The BBC was taken off Star because it cost too much and attracted dismal ratings, and to enable the development of Star's first local pay TV programming,' Mr Butcher wrote. 'It is also true that the BBC was deliberately antagonistic to the Chinese government and Mr Murdoch acknowledged years ago that this was potentially damaging to our business, but that is not why the BBC was removed.'

Mr Seth Faison, a crisis communications executive with Sitrick and Co, was a reporter for the South China Morning Post in Hong Kong from 1988 to 1991, when Mr Murdoch owned it. Mr Faison said Mr Murdoch improved the paper by spending money on it and hiring good journalists. Mr Faison said he and his colleagues never received direction on coverage from Mr Murdoch or from editors relaying Mr Murdoch's orders.

However, the Morning Post's managing director Clarence Chang, while trying to make a business deal with the government, once told the bureau's reporters that if they toned down their criticism of Beijing, 'it's good for me, it's good for you and it's good for Rupert', according to Mr Faison.

'It was clear to us that business came first and journalism came second,' Mr Faison said in an interview.

Still, Mr Faison said he and his colleagues did not soften their coverage and did not receive any more suggestions to do so.

'We are extremely proud of our journalistic tradition, a tradition that has kept governments, business and community leaders accountable for more than 50 years now,' Mr Butcher wrote. 'But we're not squeamish about the fact that our newspapers are also vibrant businesses - if they can't succeed as businesses, how can we maintain journalistic staff and pay levels?'

Mr Murdoch can be unpredictable and audacious, such as his bid for Dow Jones, and can throw even his editors into chaos when he senses a business opportunity and decides to act on it.

For example, the Australia Institute research group has criticised Chris Mitchell - editor of News Corp's national daily, The Australian - as a 'climate-change denialist' for his paper's coverage of the environment.

But on May 9, Mr Murdoch launched a surprise initiative in his global media empire to make the company 'carbon-neutral' by 2010. That threw The Australian 'into a state of frantic confusion', Mr Clive Hamilton, the institute's executive director, wrote in an e-mail. The paper's climate coverage has not changed, he said.

Mr Raymond Snoddy, a media commentator who spent eight years at the Times of London and 19 years as a media reporter at the Financial Times, said News Corp is eliminating as many as 100 journalists' jobs through buyouts and layoffs at the Times, Sunday Times, The Sun and the News of the World. He said part of the savings is being used to finance new colour printing presses worth about US$1.4 billion.

'What people don't give him enough credit for is that he's still prepared to invest in newspapers,' Mr Snoddy said. 'Show me someone else who is spending that much.'

Washington Post, New York Times

Staff writer Kevin Sullivan contributed to this article. Jordan and Sullivan reported from London.