Northgate Minerals Extends Mine Life at the Stawell Gold Mine

Increase in Both Mineral Reserves and Resources

VANCOUVER, Aug. 6 /CNW/ - (All figures in US dollars except where noted) - Northgate Minerals Corporation (TSX: NGX, NYSE Amex: NXG) is pleased to announce an increase in mineral reserves and resources at its Stawell Gold Mine located in Victoria, Australia. An aggressive exploration program in support of resource delineation and conversion has identified approximately 870,000 tonnes of additional mineral reserves containing 93,000 ounces of gold and has extended the current mine-life until the second quarter of 2012.

                   Mineral Reserve and Resource Highlights
    
    -   An additional 93,000 ounces of gold reserves have been delineated in
        the first half of 2009
    -   Stawell's mine-life has been extended until Q2-2012
    -   An additional 32,000 indicated ounces and 98,000 inferred ounces have
        been added to the mineral resource base
    
              ---------------------------------------------------------------
                     Proven             Probable                Total
    -------------------------------------------------------------------------
    June 30, Tonnes  Grade  Gold  Tonnes  Grade  Gold  Tonnes  Grade  Gold
     2009     (000)  (g/t)(000 oz) (000)  (g/t)(000 oz) (000)  (g/t)(000 oz)
    -------------------------------------------------------------------------
    Open Pit
     (less
     than 100m
     from
     surface)     -      -    -      430   1.80     25    430   1.80     25
    -------------------------------------------------------------------------
    Underground
     (greater
     than 100m
     from
     surface)    64   7.13   15    2,004   4.24    273  2,068   4.33    288
    -------------------------------------------------------------------------
    Total Proven
     & Probable
     Reserves     15,000 ounces       298,000 ounces        313,000 ounces
    -------------------------------------------------------------------------
    
    Note: Mineral reserves were estimated using a gold price of A$965/oz;
          cut-off grade applied was variable for underground ore depending
          upon width, mining method and ground conditions; dilution of 2m-3m
          and mining; recovery of 95%-100% was applied to the underground
          reserves, dependent upon mining method.

Ken Stowe, President and Chief Executive Officer, remarked, "Our exploration efforts at Stawell continue to delineate new zones of economic mineralization. In the first six months of the year, we have added another 93,000 ounces to our reserves, bringing the total increase to approximately 230,000 ounces since we acquired the mine less than 18 months ago. Equally as important, the mine reserve life has also increased to three years. Over the balance of 2009, we expect to define additional reserves in the newly discovered GG7 zone, and in the Dukes Flank and North Magdala zones and will continue to explore the Magdala Upper Levels and GG6 areas, which have great potential to host additional reserves and resources. Overall, prospects are excellent for us to add substantially to the nearly 2.0 million ounces of gold produced at Stawell over the 26-year history of the mine."

Overview of Mineral Reserve and Resource Additions

Mineral reserves and resources were increased in all areas of the mine through a combination of exploration drilling, resource definition drilling, and grade control drilling. In the first six months of 2009, a total of 870,000 tonnes containing 93,000 ounces of additional gold reserves were delineated and 48,000 ounces were depleted as a result of mining activity. The result is a net increase of 51,000 ounces of reserves compared with Northgate's December 31, 2008 reserve statement. A further 32,000 ounces of indicated and 98,000 ounces of inferred resources have also been added. Mineral resources, exclusive of reserves, at June 30, 2009 are outlined in the following table:

                    ---------------------------------------------------------
                           Indicated                      Inferred
    -------------------------------------------------------------------------
    June 30,        Tonnes     Grade     Gold     Tonnes     Grade     Gold
     2009            (000)     (g/t)   (000 oz)    (000)     (g/t)   (000 oz)
    -------------------------------------------------------------------------
    Open Pit
     (less than
     100m from
     surface)       2,975      2.19       209       205      2.64       17
    -------------------------------------------------------------------------
    Underground
     (greater
     than 100m
     from
     surface)         388      4.68        58       843      5.57      151
    -------------------------------------------------------------------------
    Total Resources  267,000 indicated ounces      168,000 inferred ounces
    -------------------------------------------------------------------------
    
    Note: Mineral Resources were estimated using the following parameters:
          a. Gold price of A$1,071/oz for underground resources
          b. Magdala surface above 130mRL and above a nominal 0.8g/t gold
          cut-off
          c. Wonga surface at A$1,071/oz gold price
    
    Continuation of the 2009 Exploration Program
    
    The balance of the 2009 exploration program at Stawell will focus on the
newly discovered GG7 (an extension to the GG5L system), Dukes Flank and North
Magdala zones, in addition to ongoing work in the Magdala Upper Levels and GG6
areas (refer to Figure 1 below) where definition and exploration drilling will
be carried out in support of resource conversion and further mine-life
extensions.
    
    Figure 1 - Stawell Gold Mine Long Section
    
    www.northgateminerals.com/Theme/Northgate/files/Releases/SGM_LS_J09.gif
    
    Note to Mineral Reserves and Resources:
    
    1.  All Mineral Reserves and Resources have been estimated in accordance
        with the JORC Code and have been reconciled to CIM Standards as
        prescribed by National Instrument 43-101.
    2.  Mineral Resources are exclusive of Mineral Reserves.
    3.  Mineral Reserve estimates were prepared by Glenn Miller, Mine
        Technical Superintendent, Northgate Minerals Corporation. Mr. Miller
        is a member of the Australasian Institute of Mining and Metallurgy
        and has over 16 years of relevant engineering experience and is a
        Qualified Person.
    4.  Mineral Resource estimates were prepared by Mark Haydon, Geology
        Manager, Northgate Minerals Corporation. Mr. Haydon is a member of
        the Australasian Institute of Geoscientists and has over 15 years of
        relevant geological experience and is a Qualified Person.
    5.  Mineral Reserves and Mineral Resources are rounded to 1,000 tonnes,
        0.01 g/t gold and 1,000 ounces. Minor discrepancies in summations may
        occur due to rounding.

The terms "Qualified Person", "Mineral Reserve", "Proven Mineral Reserve", "Probable Mineral Reserve", "Mineral Resource", "Measured Mineral Resource", "Indicated Mineral Resource", and "Inferred Mineral Resource" used in this news release are defined in accordance with NI 43-101-Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators.

Northgate Minerals Corporation is a gold and copper producer with mining operations, development projects and exploration properties in Canada and Australia. The company is forecasting record gold production of over 390,000 ounces in 2009 and is targeting growth through further acquisition opportunities in stable mining jurisdictions around the world. Northgate is listed on the TSX under the symbol NGX and on the NYSE Amex under the symbol NXG.

Forward-Looking Statements:

This Northgate press release contains "forward-looking information", as such term is defined in applicable Canadian securities legislation, concerning Northgate's future financial or operating performance and other statements that express management's expectations or estimates of future developments, circumstances or results. Generally, forward-looking information can be identified by the use of forward-looking terminology such as "expects", "believes", "anticipates", "budget", "scheduled", "estimates", "forecasts", "intends", "plans" and variations of such words and phrases, or by statements that certain actions, events or results "may", "will", "could", "would" or "might" "be taken", "occur" or "be achieved". Forward-looking information is based on a number of assumptions and estimates that, while considered reasonable by management based on the business and markets in which Northgate operates, are inherently subject to significant operational, economic and competitive uncertainties and contingencies. Northgate cautions that forward-looking information involves known and unknown risks, uncertainties and other factors that may cause Northgate's actual results, performance or achievements to be materially different from those expressed or implied by such information, including, but not limited to gold and copper price volatility; fluctuations in foreign exchange rates and interest rates; the impact of any hedging activities; discrepancies between actual and estimated production, between actual and estimated reserves and resources or between actual and estimated metallurgical recoveries; costs of production; capital expenditure requirements; the costs and timing of construction and development of new deposits; and the success of exploration and permitting activities. In addition, the factors described or referred to in the section entitled "Risk Factors" in Northgate's Annual Information Form for the year ended December 31, 2008 or under the heading "Risks and Uncertainties" in Northgate's 2008 Annual Report, both of which are available on the SEDAR website at www.sedar.com, should be reviewed in conjunction with the information found in this press release. Although Northgate has attempted to identify important factors that could cause actual results, performance or achievements to differ materially from those contained in forward-looking information, there can be other factors that cause results, performance or achievements not to be as anticipated, estimated or intended. There can be no assurance that such information will prove to be accurate or that management's expectations or estimates of future developments, circumstances or results will materialize. Accordingly, readers should not place undue reliance on forward-looking information. The forward-looking information in this press release is made as of the date of this press release, and Northgate disclaims any intention or obligation to update or revise such information, except as required by applicable law.