MightyRiverPower, the first of the state-owned power companies to be partially privatised last year, will pay a special dividend to shareholders after the latest board review of its capital management.

The Auckland-based company will pay 5 cents per share to its 102,000 shareholders on Dec. 11, with a record date of Nov. 20, it said in a statement. That amounts to about $70 million in total. The board made decision today as part of an ongoing capital management review. The company will update shareholders about capital management initiatives and the dividend policy at tomorrow's annual meeting.

"The positive outcomes we achieved in FY2014, along with our decisions around capital structure - including a successful $300 million capital bond offer - have given us some flexibility and options that have allowed us to pay this special dividend, to our shareholders," chair Joan Withers said.

In August, the company lifted its final dividend by half a cent to 8.3 cents per share, taking total distributions to 13.5 cents, 4 percent above prospectus forecast and 13 percent ahead of the dividend declared in the last financial year

Shares of the power company rose 0.9 percent to $2.84 and have gained 32 percent this year.

The former state-owned enterprise stocks benefited from the National Party retaining the Treasury benches in the September general election, with opposition party plans to impose a central electricity buying agency introducing a level of risk to investors.