Glasgow Warriors props Justin Va'a, Kevin Tkachuk and Moray Low have all signed contract extensions.
Samoan World Cup star Va'a and Canadian international Tkachuck have signed new deals until 2010, while 23-year-old Low has sealed a one-year deal.
"Kevin has become an invaluable member of our squad. As for Moray, well the world's his oyster," said head coach Sean Lineen.
"He's a fantastic local talent and an international player in the making."
Meanwhile, Lineen has announced his squad for Saturday's Magners League fixture against Munster.
"We've decided to name a 25-man squad today because of the bumps and bruises that are typical at this time of the season," said Lineen.
"It's a big last game for us with plenty to play for, especially the pride within the players, and who better to challenge ourselves against than the European finalists."
Warriors squad:
Forwards: Justin Va'a, Ed Kalman, Kevin Tkachuk, Moray Low, Dougie Hall, Fergus Thomson, Opeta Palepoi, Dan Turner, Andy Newman, Johnnie Beattie, John Barclay, James Eddie, Kelly Brown, Stevie Swindall.
Backs: Colin Gregor, Sam Pinder, Dan Parks, Andrew Henderson, Graeme Morrison, Scott Barrow, Max Evans, Thom Evans, Lome Fa'atau, Bernardo Stortoni, Hefin O'Hare.