The deal is the latest spat between the union and the company, which has former union president John Maitland as a shareholder.

Resco and the union were closely involved with the planned Doyles Creek training mine at Jerrys Plains.

The fallout has pitted the union's national president, Ian Murray, against his brother Peter, who was national secretary before resigning in a fallout with other national executive members and joining Resco.

Ian Murray said yesterday the union would have nothing to do with Doyles Creek while ever Resco was involved.

Resco founder Craig Ransley defended the deal, which covers about 160 contract workers at Rio Tinto's Hunter Valley and Mount Thorley mines.

Mr Ransley said Resco had replaced another contractor, Pegasus, at the two mines and anyone wanting to keep their job had to swap employers.

"We tendered for the contract and won it," Mr Ransley said.

"It doesn't matter that Pegasus might have paid their people more. So what? People are paid different rates all over the industry. Once they lost the contract their people didn't have to come to work for us and some didn't. They have chosen to stay with Pegasus or try their luck elsewhere."

Mr Ransley said Mr Maitland had a 5 per cent stake in Resco, which he denied was anti-union.

Peter Murray said he had resigned his paid job with the union on a matter of principle but he was not ready to retire and when Resco offered him a job he took it.

He believed he was still negotiating with the integrity he had as a union organiser and remained committed to the welfare of mineworkers.

The Herald was unable to reach Mr Maitland for comment.