S Patil, a jawan of 15 Rashtriya Rifles, was injured when infiltrating militants opened fire on Army troops, who laid an ambush near the LoC at Sundernali in Keran, they said.
Sources said the army personnel retaliated, forcing the militants to flee to the other side of LoC.
Patil was shifted to a medical unit where he succumbed to injuries, the sources said.
Eight militants were killed in the fortnight-long anti-infiltration operation in Keran Sector which was called off on October 8.