The Federal Government's sales pitch on its carbon pollution policy is getting a boost from an unlikely source - the world's biggest privately-owned coal miner.

Peabody Energy is joining the steel giant, ArcelorMittal in a $4.7 billion takeover bid for Macarthur Coal.

That prompted a jump of almost 40 per cent in the share price of the local miner.

Analysts say it indicates that international investors are not being deterred by the carbon tax, and it shoots a massive hole in the argument from the industry's lobby group about the impact of the Government's policy.

Queensland miner Macarthur Coal exports PCI (Pulverised Coal Injection) coal for use in steel-making around the world.

Peabody Energy is the world's biggest privately-owned coal producer and it already has operations in Australia.

Resources analyst Gavin Wendt from MineLife says demand for PCI coal is driving the takeover offer for Macarthur.

"This is the second crack that Peabody of the US has had for Macarthur Coal," he said.

"The company has been interested in acquiring Macarthur for some time and unsuccessful with its previous efforts, but this time it's enlisted one of Macarthur's major shareholders, ArcelorMittal.

"One would imagine that this has given Peabody a greater chance of success."

Peabody Energy and the world's biggest steelmaker ArcelorMittal have offered $4.7 billion for Macarthur Coal, or $15.50 a share (minus the company's next dividend, expected to be around 24 cents).

That is a big premium on yesterday's closing share price of $11.08.

Last year Peabody offered $16 a share for Macarthur Coal, but dropped the offer to $15 amid the mining tax.

That was rejected by China's Citic, Macarthur's biggest shareholder.

Macarthur Coal refused to do an interview with the World Today about the takeover offer, but the company told the share market it will talk to both suitors.

Gavin Wendt says Citic will be the deal maker or breaker.

"Because you have so many big groups of Macarthur registers, so many significant shareholders that wield a lot of clout, you really need the agreement of all of those shareholders like Citic if you're going to be successful," he explained.

"This has been the problem for Peabody or any other potential bidder over the years.

"The thing that Peabody has got going for it is it also seemingly has agreement, at this stage at least, from POSCO (Pohang Iron and Steel Company), which is one of the major shareholders in Macarthur."

The takeover offer has also indicated that investors are not being put off by the carbon tax.

Some mining analysts say smaller miners will be most affected by a price on carbon.

The Australian Coal Association's Ralph Hillman told ABC News 24 that the carbon price will still close mines and cost jobs despite the takeover bid.

"What we're seeing here is a high quality asset selling metallurgical coal, which is a very high value commodity. So it's not astonishing that this should take place, it certainly doesn't prove the carbon tax won't impact industry," he argued.

"What the ACIL Tasman modelling shows, that's the modelling we commissioned, was that high cost mines would probably be at risk of going under because of the tax."

Coal industry consultant, Dr Don Barnett says those claims are exaggerated.

"If you include the impact on [new] projects it could well be true. I don't see that job loss coming from the existing producers today," he said.

Justin Urquhart Stewart, from Seven Investment Management in London, says Australian companies are attractive strategically.

"I think you have to realise that the focus on mining and mining stocks and commodities is still extremely strong," he said.

"Although the global economy appears to be slowing, the access to strategic assets is seen as being absolutely vital."

He says that explains why the mining tax and the carbon tax are not putting off international interest in Australian companies.

"That's just merely an extra tax you have to pay in terms of, to gain entry to the nightclub," he explained with a metaphor.

"People want to get into the nightclub because they want to have some of the assets that are in there, but they have to pay extra fees to be able to get in, and that's just the cost of being able to do business."

He says the bid comes amid a rise in takeovers and mergers globally.

"There are a lot of people with a lot of cash around, and they all wish to pick up assets whilst they can," he said.

"So yes, be prepared for more M&A (mergers and acquisitions), and that'll be good for markets overall."