Mining company Xstrata said yesterday that certainty over the mining tax had lifted a shadow from its planned Ravensworth North mine between Singleton and Muswellbrook.

A spokesman said Ravensworth North and Mudgee's Ulan West projects had both been under a cloud, but were now likely to be approved at the next Xstrata Coal board meeting.

Ms Gillard's first promise as PM was to fix the damaging rift with the mining industry and she did it after just a week in the job.

After talks with BHP, Rio Tinto and Xstrata, Ms Gillard formally announced the deal before the opening of the stockmarket yesterday morning.

The new regime will apply to 320 companies instead of 2500, but still generate about 90 per cent of the revenue predicted under the original "super profits tax".

Despite the breakthrough, various voices on the business side of the equation remained unhappy.

Analysts were unsure of the impact last night, with some questioning how a compromise appearing to give substantial ground to the miners could still recoup $10.5 billion of the $12 billion expected in the first two years.

For most players, however, the focus of attention is now turning to the tax's impact on individual operations and on the $6 billion in regional infrastructure funding promised in the original deal.

NSW Minerals Council chief executive Nikki Williams said NSW produced 42 per cent of Australia's black coal and the state's mining communities deserved their fair share of the money raised by the new tax.

"People talk about Queensland and Western Australia as the resource states, but NSW is a big player too," she said.

Hunter MP Joel Fitzgibbon was confident the Hunter would be looked after in a distribution of "infrastructure funding for mining regions".

He agreed that "one option would be to base it on the value of the product coming out of the region".