Mighty River Power share offer final price set

NEWS RELEASE 8 May 2013

Mighty River Power Share Offer – Final Price set at $2.50 per share The Crown has advised that the Final Price for the Initial Public Offering of Ordinary Shares in Mighty River Power has been set at $2.50 per share.

Mighty River Power Chair, Joan Withers, said the determination of the Final Price was at the sole discretion of the Crown as outlined in the Offer Document.

Following the completion of the bookbuild process, Mrs Withers said the Company has been advised and the Final Price had been announced publicly by the Shareholding Ministers.

The Mighty River Power Share Offer is made pursuant to the terms and conditions set out in a combined Investment Statement and Prospectus dated 5 April 2013, as amended on 22 April 2013.

Trading of the shares (under the stockcode ‘MRP’) is expected to begin at 12.30pm (NZST) on Friday, 10 May, 1 2 on the NZX Main Board on a conditional settlement basis. Trading of the shares on the ASX (under the stockcode ‘MYT’) on a conditional and deferred settlement basis is expected to begin at 12 noon AEST (2.00pm 3 NZST) on Friday, 10 May 2013.

Shares in Mighty River Power have not been and will not be registered under the US Securities Act of 1933, as amended, and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.

KEY DATES: 10 May 2013

Allocations expected to be available Expected commencement of trading on NZX Main Board (conditional settlement basis) and ASX (conditional and deferred settlement basis)

14 May 2013

Allotment date. Expected despatch of holding statements and last day of conditional trading

15 May 2013

Shares expected to begin trading on a normal basis on the NZX Main Board and the ASX

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Application has been made to NZX Limited for permission to list Mighty River Power and to quote its shares on the NZX Main Board and all the requirements of NZX Limited relating thereto that can be complied with on or before the date of this announcement have been duly complied with.

However, NZX Limited accepts no responsibility for any statement in this announcement. The NZX Main Board is a registered market operated by NZX Limited, which is a registered exchange, regulated under the Securities Markets Act 1988.

ASX Limited (ASX) has granted permission, subject to the satisfaction of certain conditions, for Mighty River Power to be admitted to the official list of ASX and for the shares of Mighty River Power to be quoted on ASX. The fact ASX may admit Mighty River Power to the official list and quote its shares on ASX is not to be taken as an indication of the merits, or as an endorsement by ASX, of Mighty River Power or its shares. ASX accepts no responsibility for any statement on this communication. ASX is the holder of an Australian market licence granted under the Corporations Act 2001 (Cth) under which it operates its financial market and is regulated by the Corporations Act 2001 (Cth).

None of the Crown, Mighty River Power, the Joint Lead Managers or any of their respective directors, officers or employees accepts any liability or responsibility should any person attempt to sell or otherwise deal with shares in Mighty River Power before statements confirming allocations are received.

ENDS

For further information: Katherine Litten Media Relations Manager T 0272 105 337

Anna Hirst Head of Investor Relations T 0275 173 470

Mighty River Power is one of New Zealand’s largest electricity companies – with its core business based on reliable, low fuel-cost electricity generation complemented by sales to homes and businesses.

The Company generates about 17% of New Zealand’s electricity. It operates the nine hydro stations on the Waikato River, five geothermal power stations in the Central North Island and a multi-unit gas-fired station in Auckland. More than 90% of its electricity production is from renewable sources. Mighty River Power sells electricity through multiple channels and retail brands, including Mercury Energy, GLO-BUG, Bosco Connect and Tiny Mighty Power. Mighty River Power’s metering business, Metrix, provides electricity retailers with advanced metering infrastructure solutions for their residential and commercial customers.

Mighty River Power is one of the world’s largest geothermal power station owners, and has a successful track record in geothermal development, investing more than $1.4 billion in geothermal development since FY2006. The Company is applying this capability and experience – gained through domestic geothermal exploration, development, construction and operations – to invest in international growth opportunities.