Back row forward Clive Ross, lock Alan O'Connor, and scrum-half Dave Shanahan have all signed contract extensions that will keep them at Ulster until the summer of 2019, while hooker John Andrew has agreed terms to stay with the province until 2020.
Andrew, 23, is an athletic hooker who has graduated from the Hughes Insurance Ulster Academy into the senior ranks.
The Ballymena man made his senior debut for Ulster in December 2015 against Connacht and has gone on to collect 26 caps for the province.
Clive Ross, a native of Cork, joined Ulster in 2014, having nurtured his game in the All Ireland League withLansdowne. Despite not being exposed to the Academy system, the 27-year-old has relished his opportunity in professional rugby, making 52 appearances over the past three seasons.
Dublin-born O'Connor made the switch to the Ulster Academy from Leinster in 2012, and made his senior debut the same year against his former province.
Dave Shanahan, a product of Belvedere College, progressed through the age-grade system before joining the Ulster Academy, where he impressed with a number of standout performances. The 23-year-old has made 13 senior appearances for Ulster, including starts in January's Champions Cup pool games against Exeter and Bordeaux.
