France's Romain Poite and Englishman Wayne Barnes will take charge of the Heineken Cup semi-finals in Dublin and Bordeaux respectively.
The Heineken Cup and Amlin Challenge Cup referee and assistant referee appointments were made by the ERC Match Officials Sub Committee taking into consideration a comprehensive ongoing review of performances across all relevant tournaments in conjunction with the referee managers in each Union.
Throughout the competition, ERC also provides an opportunity for coaches to share their feedback on the performance of match officials and that feedback is considered in the review process.
Poite, who refereed the 2011 final, has been on duty in all seven Heineken Cup weekends to date this season and will be taking of his charge of his 50th ERC match at the Aviva Stadium.
Heineken Cup semi-finals:
Ulster v Edinburgh at Aviva Stadium, Dublin
Referee: Romain Poite (Fra)
Assistant Referees: Jerome Garces (Fra), Pascal Gauzere (Fra)
Clermont Auvergne v Leinster at Stade Chaban-Delmas, Bordeaux
Referee:Wayne Barnes (Eng)
Assistant Referees: Nigel Owens (Wal), Dave Pearson (Eng).
Amlin Challenge Cup semi-finals:
Toulon v Stade Français Paris at Stade Félix Mayol, Toulon.
Referee: Alain Rolland (Ire)
Assistant Referees: John Lacey (Irl), Dudley Phillips (Ire)
Biarritz Olympique v Brive at Parc des Sports Aguiléra, Biarritz
Referee: George Clancy (Ire)
Assistant Referees: Greg Garner (Eng), Simon McDowell (Ire)