Mabil, 19, leaves for Denmark on Tuesday, and pending a medical will start training later this week.
"I would like to thank Adelaide United for allowing me to pursue my dream of playing in Europe for a very strong and ambitious club that sets high standards," Mabil said.
"A big thank you to my coach Josep Gombau and the rest of the staff at Adelaide United for helping my development as a player and person.
"Special mention to all my team-mates who have supported my transition.
"The youth team coaches Michael Valkanis and Angelo Costanzo for picking me up as a young boy and really helping me mature into the first team.
"And of course the fans for being such great fans to play for each week.
"But most importantly my family for the support it has given me and the opportunity it has provided me in life and that is not to forget God who gave me this blessed gift to be a footballer."
Adelaide United CEO Michael Petrillo wished the flying winger all the best as Mabil prepares for his move to Europe.
"We are really pleased for Awer, he is a great young man and has been a great example to all young footballers in Adelaide," said Petrillo.
"It shows that if you have the passion and commitment you can forge a pathway through to the A-League with the Adelaide United Football Club and as in Awer's case, Europe.
"I'm sure that he will be a great addition to their team and we will miss him but understand that his desire and dream was to play in Europe.
"We are all very happy for him and pleased to have assisted in helping him achieve his goals."
