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NEWS RELEASE Exhibit 99.1 KOSMOS ENERGYⓇ KOSMOS ENERGY ANNOUNCES FIRST QUARTER 2021 RESULTS DALLAS -- ( BUSINESS WIRE ) —- May 10 , 2021-- Kosmos Energy Ltd. ( " Kosmos ” or the “ Company ” ) ( NYSE : KOS ) announced today its financial and operating results for the first quarter of 2021. For the quarter , the Company generated a net loss of $ 91 million , or $ 0.22 per diluted share . When adjusted for certain items that impact the comparability of results , the Company generated an adjusted net loss ( ¹ ) of $ 33 million , or $ 0.08 per diluted share for the first quarter of 2021 . FIRST QUARTER 2021 HIGHLIGHTS • Net Production ( 2 ) - 53,100 barrels of oil equivalent per day ( boepd ) with sales of 36,500 boepd , resulting in a material net underlift position of approximately 1.3 million barrels of oil Phase One of the Greater Tortue LNG project ~ 58 % complete at quarter end • • Completion of an upsized $ 450 million offering of senior notes due 2028 Post - quarter end , successful reserve - based lending ( RBL ) redetermination and extension • Revenues $ 176 million , or $ 53.66 per boe • Production expense - $ 46 million , or $ 13.91 per boe • • General and administrative expenses - $ 22 million , $ 14 million cash expense and $ 8 million non - cash Capital expenditures : • $ 44 million Base Business capital expenditures • $ 73 million Mauritania and Senegal • Net cash used in operating activities - $ 47 million Commenting on the Company's first quarter 2021 performance , Chairman and Chief Executive Officer Andrew G. Inglis said : “ This month marks the tenth anniversary of Kosmos ' listing on the New York Stock Exchange . In those ten years , Kosmos has evolved from a frontier explorer to a full - cycle E & P with a diverse reserve base that has increased nearly seven - fold , building the platform for continued success over the next ten years . In the first decade of the company's history , we maintained a strong focus on corporate responsibility , leading on transparency and positioning the business to deliver value to our stakeholders through the energy transition . 2021 is off to a strong start with momentum building across the business . We have begun infill drilling activities in Ghana and the Gulf of Mexico , will soon begin drilling in Equatorial Guinea , and are on track to deliver our