Petrochemical company Ineos has bought a majority share in a licence for shale gas exploration and development in Scotland.

The company said it had purchased a 51% share in an onshore oil and gas licence surrounding its refining and petrochemical complex at Grangemouth.

The licence covers 329 square kilometres of the Midland Valley in Scotland, where the British Geological Survey has estimated there are "modest" shale gas and oil resources.

Grangemouth is being developed to import shale gas ethane from the US, where vast amounts of unconventional gas has been extracted using the controversial process of fracking.

The announcement comes as campaigners stage protests around the country for a day of action against developing fracking in the UK.

Gary Haywood, chief executive of Ineos Upstream, the company's new oil and gas exploration and production business, said: "This is a logical next step for Ineos and we are very excited about it. With our large asset base, existing operational capabilities and exemplary safety and environmental record, we are well placed to become a major player in the UK onshore gas production sector."

He added: "Over the last year INEOS Upstream has been drawing together a team of experts in the sector, including a number of leading shale exploration and development specialists from the US. This expertise gives us the perfect platform to move into onshore exploration."