County champions Essex begin the defence of their title in 2018 against Yorkshire at Headingley on 13 April.
Australia batsman Aaron Finch signs a two-year contract to play Twenty20 cricket for Surrey.
England quartet Mark Stoneman, Ben Foakes, Jason Roy and Tom Curran extend their Surrey deals for at least three more years.
Seam bowlers Jade Dernbach and Stuart Meaker sign new three-year contracts with Division One side Surrey.
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Former Sri Lanka captain Kumar Sangakkara reflects on his career as he plays his final first-class match for Surrey.
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