The Perth-based company last November offered $2.06 cash per partly paid security, representing a 15.5% premium to the three-month weighted average price of AIH securities.
The offer closed on Monday and Alinta plans to compulsorily acquire all its outstanding fully paid ordinary securities.
AAP yesterday reported that the utility had now achieved a 96.2% relevant interest of AIH.
At the time it made the offer last year, Alinta said it would buy AIH back after the poor performance by its shares since its initial public offering in October 2005.
AIH, which was spun-off from the WA utility, consists of a portfolio of power stations and gas pipelines Alinta bought from US-based Duke Energy.
