The Honduran winger has been in impressive form, scoring five goals and providing four assists in 17 appearances for the Polish side since joining them on loan.
Poznan are eager to keep the talented attacker, who Celtic purchased for £3.4m from Aris Thessaloniki in the summer of 2023.
However, they face a significant financial hurdle.
As part of the loan agreement, Celtic included a release clause that would require Poznan to shell out nearly twice their record transfer fee if they wish to make Palma’s move permanent.
Poznan’s director of communications, Maciej Henszel, disclosed this information during an interview on a local Polish radio station.
He revealed that acquiring Palma permanently would involve doubling their current record, which stands at £2m for Yannick Agnero.
Mr Henszel said: “We have a release clause. It doesn’t seem possible to lower it. I don’t think it’s negotiable. It’s not an easy matter.
“To buy Palma, we have to break our transfer record by about two times.
“In the spring, we’ll decide whether the club can afford such a transfer and whether Luis can maintain his form.”