Centre Darren Cave, number eight Robbie Diack and prop Declan Fitzpatrick have extended their contracts at Ulster.
South African Diack will be eligible to play for Ireland next July under the three-year residency rule and has joined Cave in extending his contract to the end of the 2012-2013 season.
It will come as a boost for Cave, who was overlooked for the Ireland squad for the November international series.