Centre Mignardi, full back Germain and fly-half Sola have committed to the club for a further two years, ensuring they will remain at the Stade Domenech until at least the end of the 2015/16 season.
Mignardi has been with Brive since 2011, having previously played for Auch, Agen, ASM Clermont Auvergne and Biarritz Olynpique. The 27-year-old has two French caps to his name from the 2007 summer tour to New Zealand and is a crowd favourite with the Black and Whites.
Germain had previously just been on loan from Racing Metro but a string of impressive showings have prompted head coach Nicolas Godignon to offer the 23-year-old a permanent deal.
Sola's season so far has been more disjointed given that he has slipped to second in the playmaking pecking order behind South African Riaan Swanepoel, but he has featured in both Amlin Challenge Cup fixtures and will be hoping for more game time when the tournament returns in just over a week's time.
The backline trio are the latest in a wave of re-signings at Brive, with Fijian stars Sisaro Koyamaibole and Dominiko Waqaniburotu having recently extended their contracts and Godignon and fellow coaches Casadeï Didier and Philippe Carboneau also pledging their futures to the side.
Brive currently sit ninth in the Top 14 table after five wins, six loses and a draw in the first 12 games but they could have been as high as fifth had they not slipped to a surprise home defeat to Biarritz last time out. A bonus-point win over the bottom-placed team would have put them on 32 points, just four shy of leaders Toulon and Clermont.
The 1997 Heineken Cup winners do top the standings in their latest continental campaign, though, with a 20-20 draw at Calvisano and a 23-16 success against Newcastle leaving them with a one-point cushion over the Falcons and Bucharest Wolves ahead of their trip to Romania a week on Saturday.