EXHIBIT 99.1

Press Release

For Immediate Release

Acquisition of the Sponsor of the iShares S&P GSCI Commodity-Indexed Trust is Completed

San Francisco, CA, December 1, 2009 - Today the previously announced transaction between Barclays PLC, the ultimate parent company of (i) Barclays Global Investors, N.A., the Trustee (the “Trustee”) of the iShares S&P GSCI Commodity-Indexed Trust (the “Trust”); (ii) Barclays Global Investors International, Inc., the Sponsor (the “Sponsor”) of the Trust and manager of the iShares S&P GSCI Commodity-Indexed Investing Pool LLC (the “Investing Pool”); and (iii) Barclays Global Fund Advisors, the Advisor (the “Advisor”) of the Investing Pool and BlackRock, Inc. (the “BlackRock Transaction”) was consummated. The BlackRock Transaction included the acquisition by BlackRock Inc. of the Trustee of the Trust, the Sponsor of the Trust, who is also manager of the Investing Pool, the Advisor of the Investing Pool and certain of their affiliated companies.

In connection with this change of ownership, the name of the Trustee was changed to BlackRock Institutional Trust Company, N.A., the name of the Sponsor was changed to BlackRock Asset Management International Inc., and the name of the Advisor was changed to BlackRock Fund Advisors.

It is not expected that the BlackRock Transaction will materially affect the Trust, its shareholders, or an investment in its shares.

Contacts for Press:

All Other Inquiries:

www.ishares.com or 1-800-iSHARES (1-800-474-2737)

The iShares® S&P GSCI^TM Commodity-Indexed Trust (the “Trust”) and the iShares® S&P GSCI^TM Commodity-Indexed Investing Pool (“Investing Pool”), in which the Trust invests all its assets, are each commodity pools as defined in the Commodity Exchange Act and the applicable regulations of the CFTC. The Sponsor of the Trust is BlackRock Asset Management International Inc., (“BAMII”), a commodity pool operator (“CPO”) registered with the CFTC. BAMII is also the Manager and CPO of the Investing Pool. BlackRock Fund Advisors (“BFA”) serves as the commodity trading advisor of the Investing Pool and is registered with the CFTC. BlackRock Fund Distribution Company (“BFDC”), a broker-dealer and FINRA member, provides promotional

support to the Trust. BFDC is a subsidiary of BAMII. BFA is a subsidiary of BlackRock Institutional Trust Company, N.A. (“BITC”), a national banking association and the Trustee. BAMII and BITC are affiliates of BlackRock, Inc. Neither the Trust nor the Investing Pool is an investment company registered under the Investment Company Act.

Investments in shares of the Trust are speculative and involve a high degree of risk. You could lose all or a substantial portion of your investment in the shares of the Trust. Before making an investment decision, you should carefully consider the risk factors and other information included in the prospectus. The value of the shares of the Trust, which seeks to track the S&P GSCI^TM Total Return Index (“Index”), depends on the value of CERFs held by the Investing Pool, which are futures contracts on the S&P GSCI^TM Excess Return Index (“S&P GSCI-ER”), and will fluctuate based on the prices of commodity futures contracts reflected in the S&P GSCI-ER. Commodities markets have historically been extremely volatile. Shares may outperform or underperform the Index.

The price you receive upon the sale of your shares may be less than their NAV. The NAV will fluctuate with changes in the market value of the Investing Pool’s assets, and market supply and demand. Brokerage commissions and fees will reduce returns.

Although shares of the Trust may be bought or sold on the exchange through any brokerage account, shares of the Trust are not redeemable from the Trust except in one or more blocks of 50,000 units called Baskets. Only institutions that become Authorized Participants may purchase or redeem Baskets.

Shares of the Trust may not provide the anticipated benefits of diversification from other asset classes. The lack of an active trading market for the shares may result in losses on your investment at the time of disposition of your shares. The Trust and the Investing Pool have no operating history. Therefore, there is no performance history to serve as a factor for evaluating an investment in the shares.

The iShares S&P GSCI Commodity-Indexed Trust issues shares representing fractional undivided beneficial interests in its net assets. The Trust is registered under the Securities Act of 1933 of the United States but is not registered for distribution, or traded, anywhere outside the United States. Please note that, since the shares of the Trust are expected to reflect the price of commodities, as described more fully in the prospectus, held by the Trust, the market price of the shares will be as unpredictable as the price of those commodities have historically been.

The price received upon the sale of shares of the iShares S&P GSCI Commodity-Indexed Trust, which trade at market price, may be more or less than the value of the commodities represented by them. If an investor sells the shares at a time when no active market for them exists, such lack of an active market will most likely adversely affect the price received for the shares. For a more complete discussion of risk factors relative to the iShares S&P GSCI Commodity-Indexed Trust, carefully read the prospectus.

Following an investment in the iShares S&P GSCI Commodity-Indexed Trust, several factors may have the effect of causing a decline in the prices of the commodities and a corresponding decline in the price of the shares. Among them: (i) a change in economic conditions, such as a recession, can adversely affect the price of the commodities. These commodities are used in a wide range of industrial applications, and an economic downturn could have a negative impact on its demand and, consequently, its price and the price of the iShares; (ii) a significant change in the attitude of speculators and investors towards the commodities. Should the speculative

community take a negative view towards the commodities, a decline in world commodities prices could occur, negatively impacting the price of the Trust; (iii) a significant increase in the commodity price hedging activity by commodities producers.

The Trust is not sponsored, endorsed, sold, or promoted by Standard & Poor’s or its affiliates. Neither Standard & Poor’s, nor its affiliates, make any representation regarding the advisability of investing in the Trust.

© 2009 BlackRock Institutional Trust Company, N.A. All rights reserved. iShares^® is a registered trademark of BlackRock Institutional Trust Company, N.A. All other trademarks, servicemarks or registered trademarks are the property of their respective owners.

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