Anglo-Swiss mining group Xstrata said Monday it had suspended exploration for new mines in the Australian state of Queensland in reponse to federal government plans for a tax on mining. 'We have decided to suspend exploration activities in north Queensland until there is greater certainty on the fiscal regime for future mining developments,' said Steve de Kruijff, chief operating officer for Xstrata Copper North Queensland. He also warned in a statement that the proposed tax increases could 'deter the reinvestments that are necessary to sustain our existing operations' in Queensland. Australian Prime Minister Kevin Rudd has put forward a 40 percent tax on miners' 'super profits,' prompting uproar in the mining industry. Xstrata argued that the tax would upset the viability of copper mining in Australia compared to other parts of the world and introduced greater uncertainty into the financial prospects for any new mines. 'Exploration is the lifeblood of the mining industry but it is not possible to justify Xstrata Coppers ongoing funding of additional exploration activities when the fundamental economics of the industry in Australia are being challenged,' de Kruijff added. Xstrata said the exploration programme in the Mount Isa and Cloncurry districts involved planned expenditure of around 30 million Australian dollars (27 million US dollars, 21 million euros) over the next three years. The group's copper mining, smelting and refining operations in north Queensland employed more than 3,500 people, and contributed 'more than 1.3 billion' to the Queensland economy in 2009, the company claimed An opinion poll on Monday indicated that public support for Rudd has plunged after he proposed the new resources tax. 