Multi-millionaire former banker Malcolm Turnbull was sworn in as prime minister of Australia on Tuesday, just hours after masterminding a coup against conservative leader Tony Abbott, and pledging a new style of leadership.

Turnbull is the country's fourth prime minister in just over two years, a recent Australian political tradition the deposed Abbott slammed as a "revolving door" that was not good for the country.

"This is the most exciting time to be an Australian," Turnbull told reporters in the capital before taking the oath.

"This is a turn of events I did not expect, I have to tell you, but it's one that I'm privileged to undertake, and one that I'm certainly up to."

Turnbull, a suave former lawyer, has pledged to run a consultative government, in contrast to Abbott's divisive rule.

"My firm belief is that to be a successful leader in 2015, perhaps at any time, you have to be able to bring people with you by respecting their intelligence in the manner you explain things," he said Monday. "We need advocacy, not slogans."

Abbott lashed out at the savage nature of modern politics after his sudden toppling by his long-time Liberal Party colleague and rival -- who served as communications minister before making the challenge.

"The nature of politics has changed in the past decade. We have more polls and more commentary than ever before, mostly sour, bitter character assassination," Abbott told a farewell press conference.

He won power in a general election victory in September 2013 but his first budget, with its harsh cuts to health and education, proved highly unpopular.

Abbott survived a leadership challenge in February after poor polling and a series of gaffes ignited a backbench revolt.

But he failed to turn around the polls, bolster the economy or stop damaging internal leaks, and lost the support of his party.

- New blood -

The new leader, with strong support from influential foreign minister Julie Bishop who the party re-elected as deputy leader with a 70-30 vote in her favour, is expected to shake up the cabinet later this week.

He is thought likely to sweep out traditional conservatives and bring in younger blood and more women.

Turnbull, whose successful career has included stints as a barrister and an entrepreneur, ruled out an early national election to cement his leadership.

He said over the coming weeks and months he would set out his economic policy, but gave no details.

"Opportunities that are there in the global economy, built on the foundations in no small measure of the free trade deals, are enormous," he said.

Australia's economy has slowed over the past year as the nation struggles to transition away from the mining-led growth that has helped avoid recession for 24 years.

Unemployment is hovering around a decade-high, wages growth is subdued, while government revenue has been hit by slowing commodities demand from China, Australia's largest trading partner.

Nick Economou, senior lecturer in politics at Monash University in Melbourne, said it was too early to say whether Turnbull would be able to charm the electorate and turn around the government's fortunes.

"A lot depends on the economic argument he intends to make," he said.

"I think there is a real danger for Turnbull here because... the problem in the Australian economy is the mining boom is over, government expenditure is outstripping revenue raising and he will face the same problem that Tony Abbott faced."

Turnbull -- who was ousted by Abbott as Liberal Party leader in 2009 over his support of the previous Labor government's carbon emissions trading scheme -- also said there would be no change to Australia's climate policy.

With its heavy use of coal-fired power and relatively small population of 23 million, Australia is considered one of the world's worst per capita greenhouse gas polluters.

Canberra's targets for reducing emissions over the next 15 years by 2030 have been criticised as well below the level required by the government's own advisory body, the Climate Change Authority.
Source: AFP