Interim Management Statement

11 August 2010

3i Infrastructure plc - Interim Management Statement

3i Infrastructure plc ("3i Infrastructure" or "the Company") is an investment company focusing on infrastructure investment opportunities globally. This Interim Management Statement is issued in accordance with FSA Disclosure and Transparency Rule 4.3. This statement relates to the period from 1 April 2010 to 10 August 2010.

Summary

·; Portfolio assets continue to perform well, generating good income

·; Current cash balances of £296 million

·; Attractive pipeline of investment opportunities

·; Florence Pierre appointed to the Board of Directors

Peter Sedgwick, Chairman of 3i Infrastructure, said: "The assets in the portfolio continue to perform well operationally and financially, generating good income and supporting the delivery of the Company's yield objective."

Cressida Hogg, Managing Partner for Infrastructure, 3i Investments plc, added: "We are confident about the market for infrastructure investment, and continue to build on our attractive pipeline of investment opportunities."

1. Portfolio and returns

3i Infrastructure's portfolio is performing well operationally and financially, and is positioned to deliver a robust yield. Dividends and interest received in the first quarter to 30 June 2010 resulted in a cash inflow of £15.2 million.

As usual, an important element of the determination of the results for the period to 30 September 2010 will be the valuation exercise carried out on the investment portfolio as at that date. 3i Infrastructure will issue a pre-close update in late September 2010 and will issue its results for the six months to 30 September 2010, including the net asset value as at 30 September 2010, in November 2010.

2. Balance sheet

Following the payment of the final dividend for the year to 31 March 2010 of £26.8 million, and in light of continued robust income generation from the portfolio during the period, at 10 August 2010 the Company had cash balances of £296 million.

3. Appointment of Florence Pierre to the Board

As announced separately this morning, Florence Pierre will be appointed as a non-executive Director of the Company with effect from 1 September 2010. Florence Pierre has significant experience in financial services, and will be a valuable addition to the Board.

Ends

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3i Infrastructure plc is a Jersey-incorporated, closed-ended investment company that invests in infrastructure businesses and assets and is regulated by the Jersey Financial Services Commission. The Company listed on the London Stock Exchange in March 2007, raising £703 million in an initial public offering and a further £115 million in a subsequent placing and open offer in July 2008. The Company is a constituent of the FTSE 250 index. It aims to build a diversified portfolio of infrastructure investments across the globe, but with an initial focus on Europe, Asia and North America.

3i Investments plc, a wholly-owned subsidiary of 3i Group plc, is authorised and regulated in the UK by the Financial Services Authority and acts as Investment Adviser to 3i Infrastructure plc.

This press release is not for distribution (directly or indirectly) in or to the United States, Canada, Australia or Japan and is not an offer of securities for sale in or into the United States, Canada, Australia or Japan. Securities may not be offered or sold in the United States absent registration under the U.S. Securities Act of 1933, as amended (the "Securities Act"), or an exemption from registration under the Securities Act. Any public offering to be made in the United States will be made by means of a prospectus that may be obtained from the issuer or selling security holder and will contain detailed information about 3i Group plc, 3i Infrastructure plc, the 3i India Infrastructure Fund and management, as applicable, as well as financial statements. No public offering in the United States is currently contemplated.

This statement aims to give an indication of material events and transactions that have taken place during the period from 1 April 2010 to 10 August 2010 and their impact on the financial position of 3i Infrastructure plc. These indications reflect the Board's current view. They are subject to a number of risks and uncertainties and could change. Factors which could cause or contribute to such differences include, but are not limited to, general economic and market conditions and specific factors affecting the financial prospects or performance of individual investments within the portfolio of 3i Infrastructure plc.