Raheem Mostert officially wants OUT of SF after helping lead the 49ers to a Super Bowl … the RB’s agent says contract talks with the team have failed — and now, he’s demanding a trade.

The 28-year-old — who rushed for a staggering 220 yards and 4 TDs in the NFC Championship Game win over the Packers — has been angling for a raise since the season’s end.

But, Mostert’s agent said Wednesday the Niners won’t budge … so Raheem wants to play elsewhere now.

“After months of unproductive talks with the 49ers about fairly adjusting Raheem Mostert’s contract (which paid him for special teams) we have requested a trade,” agent Brett Tessler said.

“Disappointing that it would come to this for a guy who led all NFL RBs in YPC & helped lead them to the Super Bowl.”

Mostert came out of nowhere to become a star for the Niners this past year … rushing for 772 yards and 8 TDs on only 137 carries in the regular season.

Raheem signed a 3-year, $8.7 million deal with the 49ers before the 2019 season … but clearly he feels he’s worth well over that now.

Question is … if he’s traded, is there an NFL team ready to pay up for him?