(NZ$91 million), Highbank/Montalto ($37 million) and Matahina ($115 million) hydro power stations. 1998 electricity sector reforms In 1998 the New Zealand Government passed the Electricity Industry Reform Act 1998 which was intended to change the structure of the electricity industry to encourage competition. This Act required the operational separation of lines and generation business activities by 1 July 1999 and separation of the ownership by 1 January 2004. As by now Trustpower had built up a substantial generation portfolio it elected to be a generator/retailer and so sold its lines and its contracting business, PowerLink Limited. Following a competitive sales process, TrustPower sold its lines business to United Networks Limited (formerly Power New Zealand) for $485 million. Trustpower also acquired the retail business from eight energy companies: Waipa Power, Wairoa Power, Marlborough Electric, Buller Electricity, Westpower, Electricity Ashburton, Central Electric, and Otago Power. Using the proceeds of the sale of these businesses Trustpower began purchasing the generation assets being shed by those energy companies that had opted to be a lines company. This led to it purchasing the following hydro power stations and schemes: Arnold, Branch and Waihopai, Kumara, Mangorei, Motukawa, Paerau, Patearoa, Patea (for $72m) Wahapo, Waipori (for $70m) as well as the Tararua Wind Farm (for $49m). Thus by March 1999 it had 421.5 MW of installed capacity, capable of generating up to 1,769 GWh per annum. In March 2003 Trustpower completed the purchase of the Cobb Power Station for $92.5m from NGC. Share buyback In 2003 Trustpower bought back some of its shares. Infratil did not participate in the buy-back, which lead to it increasing its shareholding to 33.5%. In 2006 Infratil purchased Allient Energy's shareholding for NZ$6.20 a share, which gave it 51% and thus majority control of Trustpower. Expansion In 2013, Trustpower bought Energy Direct, a Whanganui electricity and gas company. In 2015, it bought 65% of King Country Energy Ltd from Nova Energy. King Country Energy generates all of its electricity from renewable sources (principally hydro-electric generation) and supplies electricity to the Waitomo, King Country and Ruapehu Districts. King Country Energy was incorporated in 1991. On 18 December 2015, Trustpower announced that it was considering a process to demerge its wind assets in Australia and New Zealand, separating into two New Zealand incorporated listed companies by way of a Court-approved scheme of arrangement. The Demerger, effective on 31 October 2016, resulted in the creation