The Dane finished last season on loan at Elland Road and United negotiated an option with Brondby to sign Ankergren permanently as part of the original loan deal.
Leeds were prevented from taking up the option, however, until their transfer embargo was lifted by the Football League last week.
Ankergren remained in Denmark for much of the summer and missed most of United's pre-season schedule, but he made a 45-minute appearance last night as a young Leeds side rounded off the club's warm-up for the new campaign with a 2-0 defeat at Guiseley.
Former Bolton Wanderers and Celtic midfielder Alan Thompson made a lesser impact due to injuries, but is now fully-fit again and will be installed as the club captain after leading by example in pre-season training without the security of a guaranteed contract.
"He's waited and waited to sign a contract, and that shows he is willing and wants to achieve something here," said Wise. "He will be captain, he's my experienced one, he's very important to me."
Wise admits that it will be a 'busy week' for transfer activity with deals also understood to be imminent for the various trialists who have played in the majority of the pre-season friendlies.
Leon Constantine (Port Vale), David Prutton (Southampton) and midfielder Curtis Weston (Swindon Town) are all ready to sign along with defenders Rui Marques and Matt Heath, who played last season, and former Chelsea striker Tore Andre Flo.