UK's Tullow Oil plunges most in almost 7 years after Ghana tax tribunal ruling

** Shares of Tullow Oil TLW.L plunge almost 49% to 9.8p; on track for worst day since December 2019

** Stock of the West Africa-focused independent oil and gas explorer among the top losers on the London market

** International Chamber of Commerce tribunal rules against TLW's $196.5 million tax dispute with Ghana

** Rejects company's claim that Ghana's corporate income tax assessment on insurance proceeds received between 2016 and 2019 breached its petroleum agreements

** Tribunal also rules that penalties equivalent to 100% of tax assessment not covered by Tullow's contractual protections

** Including session's losses, TLW down about 62% YTD