US oil supermajor, ExxonMobil is all set to pour £500 million to upgrade Britain’s largest oil refinery and extend its facility. Almost a century-old Fawley refinery will see the addition of new oil processing units, enabling it to produce larger volumes of high-quality diesel. The upgradation is in line with Exxon’s growth plans to double earnings by 2025 with Fawley marked as a “strategic” site.