Former Hull and Newcastle forward Hatem Ben Arfa will not be able to play for Nice this season under FIFA rules.
Hull are in talks to sign Aaron Lennon on loan from Tottenham for the rest of the season, Sky sources understand.
The Spanish club have confirmed the Nigerian striker has parted company with them after the exit fee in his contract was paid via the league on Monday.
"Footballer Obafemi Martins has this afternoon placed at the headquarters of the Professional Football League (LFP) the amount corresponding to the termination clause in his contract with Levante UD," said a Levante statement.
That release fee is reportedly in the region of three million euros.
Martins scored nine goals in 27 appearances for Levante since joining from Rubin Kazan in the summer.
The well-travelled 28-year-old former Inter Milan and Newcastle striker is now expected to fly to the United States to complete his move to the Sounders, who would become his eighth club.