In a deal said to be worth £54 million, Swiss-based petrochemicals giant Ineos plans to buy out Finnish energy company Fortrum to take control of a gas-fired combined heat and power plant (CHP), which supplies its Grangemouth refinery in Scotland.

Ineos said the takeover is in connection with its construction of a £300 million ethane gas terminal at the Scottish complex on the Firth of Forth.

The Grangemouth CHP generates 145 megawatts of power and 257 megawatts of heat, providing electricity and steam to the site's petrochemical operations. Excess electricity sold on to the UK's national grid.

In July, the UK government awarded Ineos a £230 million loan guarantee to build what will be the largest ethane storage tank, fulfilling a promise made in the aftermath of an industrial dispute at Grangemouth.

In August, Ineos announced it would enter shale gas exploration after agreeing to take a 51% stake in an exploration licence area in from BG Group. The license covers a stretch of land surrounding the Scottish complex.

John McNally, chief executive of Ineos Olefins and Polymers UK, called the latest investments "another key milestone in creating a successful future for the site and those businesses that depend upon its continued presence in Scotland."