Nigel Owens of Wales will referee his 100th tournament match when he takes charge of the Champions Cup final between ASM Clermont Auvergne and Saracens at BT Murrayfield on Saturday 13 May.Ireland’s John Lacey has been appointed to referee the Challenge Cup decider between Gloucester Rugby and Stade Francais Paris on Friday 12 May at the same venue, while Mike Adamson of Scotland will be in the middle for the meeting of Enisei-STM and Krasny Yar in the all-Russian Continental Shield final on the BT Murrayfield back pitches.BUY TICKETS | Champions Cup FinalThe appointments were announced today (Wednesday 13 May) by EPCR’s selection committee, which is chaired by the tournament organiser’s Head of Match Officials, Joel Jutge.Currently the world’s most experienced referee, Owens performed strongly in both the tournament quarter-final and semi-final and will be taking charge of European club rugby’s showpiece match for the third year in a row.His assistant referees in Edinburgh will be Ireland’s George Clancy and Ian Davies of Wales.Lacey will be refereeing the Challenge Cup final for the second year in a row and his assistant referees will be Andrew Brace of Ireland and Wales’ Ben Whitehouse.2017 Challenge Cup final – Friday 12 MayGloucester Rugby v Stade Francais Paris, BT Murrayfield (kick-off 8pm)2017 Continental Shield final – Saturday 13 MayEnisei-STM v Krasny Yar Saturday, BT Murrayfield complex (kick-off 12 noon)2017 Champions Cup final – Saturday 13 MayASM Clermont Auvergne v Saracens, BT Murrayfield (kick-off 5pm)