Ramon Nunez has agreed to have his Leeds contract terminated.
Nunez has not played for the club since April and was not given a squad number at the start of the season.
The Honduran midfielder's deal has been scrapped by mutual consent, and he is now free to find another club.
Nunez made 25 appearances in two-and-a-half years with Leeds following a 2010 move from Deportivo Olimpia.
The 18-year-old made his debut last season after progressing through Rovers' youth academy and has scored five goals in as many starts and 18 substitute appearances.
Manager Ronnie Moore said: "Cole is a promising young striker who deserves this opportunity.
"We've seen glimpses of his talent this season and I believe there is a lot more to come from him.
"He has a great attitude, wants to improve and has a bright future at the club."
Stockton added: "I'm really pleased with my new contract.
"I'm grateful to the manager for giving me this chance and hopefully I'll repay him and the club with my performances."
