The tourism heavyweight signed an agreement to buy the business on Friday, making it the full owner of the company which offers a variety of horse-riding experiences in and around the area.
Present Dart Stables owner Peter Davies said after 21 years he was ``delighted'' to be handing the reins over to NTT.
``This has been a wonderful journey and I know Ngai Tahu Tourism will take good care of the staff and horses that I'm leaving behind and also take commercial horse-trekking to another level.''
Mr Davies thanked the ``fantastic and loyal staff'' who had been involved with the business since it was established in 1992, and his ``lovely wife Jenny, without whom none of this would have been possible''.
The operation attracts more than 11,000 customers a year.
Ngai Tahu Tourism chief executive Quinton Hall said the purchase was an ``ideal fit'' for the company and would complement its range of experiences in the region.''
NTT will officially take over the company on December 1.
It recently acquired Glacier Southern Lakes Helicopters in Queenstown and entered into a joint venture in the star-gazing business Earth & Sky in Tekapo.
