Net interest costs fell to $166.2m from $178.2m, reflecting lower interest rates on the floating portion of the debt portfolio, increased interest earned on deposits and the replacement of expiring debt with a lower cost $250m US private placement in 2010.
Vector declared a final dividend of 7.5c per share for the year, unchanged from last year's final dividend.
The total dividend for the year was 14.5c, up from 14.25c declared in the previous year.
In addition to its electricity and gas distribution businesses, Vector operates fibre optic networks in Auckland and Wellington, which deliver high speed broadband services.
The company is 75.1 per cent owned by the Auckland Energy Consumer Trust, whose beneficiaries are Vector's customers in Auckland, Manukau and parts of the Papakura. Shares in Vector last traded at $2.70.