British shale gas company IGas has more than doubled its estimate of gas in place at its site in north-west England.
IGas chief executive Andrew Austin said shale gas reserves at its Ince Marshes site in Cheshire could be more than twice its pre-drill estimates of up to 4.6 trillion cubic feet, boosting Britain's reserves to levels above Poland's, until now the focus of the shale gas industry in Europe.
"When you combine our estimates with Cuadrilla's flow results, you're looking at probably a shale that's going to be better than what has been seen in Europe, definitely better than Poland," said Austin.
Cuadrilla Resources suspended fracking in May 2011 at a site near Blackpool after its fracking operations caused tremors in the nearby area.
Austin said that IGas was now looking for a partner to further develop its shale gas resources
"Following a number of enquiries from interested parties, we are now launching a process to engage a suitable farm-in partner to participate in drilling further wells to corroborate these results and to develop our shale resource."
Austin said IGas would produce gas only if it could be done "in a way that's acceptable" to the local community.
The future of shale gas exploration in Europe is unclear because of environmental concerns and lack of regulatory clarity.
In March, Poland slashed its shale gas reserves to 346-768 billion bcm, some 90 per cent lower than previous estimates.
These figures knocked Poland out of the top 20 countries with the highest shale gas reserves and put it behind other European countries such as France, Norway, Ukraine and Sweden.
Previously the EIA had ranked Poland at 11th globally, ahead of France.
Figures for Britain were not yet available for publication in this ranking, but should IGas's new estimates of over 260 bcm of reserves prove accurate, its combined potential with Cuadrilla would probably push Britain's reserves ahead of Poland's.
The UK government expects to make an announcement on whether Cuadrilla can resume fracking in due course, a spokesman for the Department of Energy and Climate Change said.
In continental Europe, France and Bulgaria both put a moratorium on shale gas exploration in 2011 citing environmental concerns.