English referee Chris White will take charge of the Munster's Heineken Cup semi-final clash against Stade Francais in Lille on April 21.
Frenchman Joel Dume has been awarded the all-English clash between Leicester and Gloucester at Watford on the same day.
In the European Shield Irishman David McHugh controls the semi-final between Narbonne and Agen and Scottish official Jim Fleming will control Newcastle's clash with Harlequins on April 22.