Germany plans to draw up new regulations for hydraulic fracturing, or fracking, before the parliamentary summer recess in August.

While the regulations will allow fracking in some areas under some circumstances, economics minister Sigmar Gabriel said the government would set tough environmental standards that will all but rule out the widespread exploration of shale gas.

Environment ministers in most of the federal states would prefer to ban the practice altogether.

Under the coalition agreement between the Christian and Social Democrats who share power in Berlin, unconventional fracking using toxic substances will be banned, said environment minister Barbara Hendricks.

Some chemical producers, notably BASF - which owns oil and gas company Wintershall, are eager to test fracking. Wintershall has been active in conventional gas production in the region near the Dutch border for many years.

Olaf Lies, economics minister of the state of Lower Saxony, told the news agency Reuters that, while he wants a clear legal framework to allow fracking for conventional gas, he is against using the practice to produce shale gas which is usually found nearer to water supplies.

Germany's WEG oil and gas association welcomed the prospect of a clear legal framework. "We think the conditions will be tough but we hope this will at least be a first step and that we can push ahead with fracking for conventional tight gas, of course under the terms set for environmental checks," said a spokeswoman.

Wintershall said it welcomed any steps that would help develop conventional gas reserves with the help of hydraulic fracturing and said Germany should also allow research into fracking for shale gas to better assess the risks involved, "irrespective of whether or not there will be future commercial use in Germany."

Two years ago, the Federal Institute for Geosciences (BGR) estimated the country's shale gas potential at 0.7-2.3 trillion cubic meters.