Filed by: BHP Billiton Plc

and BHP Billiton Limited

Pursuant to Rule 425 under the Securities Act of 1933

Subject Company: Rio Tinto plc

Commission File No.: 001-10533

The following are slides comprising a presentation that was given by Graeme Hunt, President Uranium and Olympic Dam Development, BHP Billiton at the Macquarie Australian Conference on May 7, 2008.

Uranium: A clear future Macquarie Australian Conference Graeme Hunt – President Uranium and Olympic Dam Development

Page 2 Page 2 Page 2 Disclaimer This presentation is for information purposes only and does not constitute or form part of any offer or invitation to acquire, sell or otherwise dispose of, or issue, or any solicitation of any offer to sell or otherwise dispose of, purchase or subscribe for, any securities, nor does it constitute investment advice, nor shall it or any part of it nor the fact of its distribution form the basis of, or be relied on in connection with, any contract or investment decision. The views expressed here contain information that has been derived from publicly available sources that have not been independently verified. No representation or warranty is made as to the accuracy, completeness or reliability of the information. This presentation should not be relied upon as a recommendation or forecast by BHP Billiton. This presentation contains certain forward-looking statements relating to the business, financial performance and results of BHP Billiton and/or the industry in which it operates.  Forward-looking statements concern future circumstances and results and other statements that are not historical facts, sometimes identified by the words “believes”, “expects”, “predicts”, “intends”, “projects”, “plans”, “estimates”, “aims”, “foresees”, “anticipates”, “targets”, and similar expressions. The forward-looking statements contained in this presentation, including assumptions, opinions and views of BHP Billiton or cited from third party sources are solely opinions and forecasts which are uncertain and subject to risks. For more detail on those risks, you should refer to the sections of BHP Billiton's annual report on Form 20-F for the year ended 30 June 2007 entitled “Risk factors”, “Forward looking statements” and “Operating and financial review and prospects” filed with the US Securities and Exchange Commission (the "SEC"). A multitude of factors can cause actual events to differ significantly from any anticipated development. Neither BHP Billiton nor any of its subsidiary undertakings nor any of its officers or employees guarantees that the assumptions underlying such forward-looking statements are free from errors nor does any of the foregoing accept any responsibility for the future accuracy of the opinions expressed in this presentation or the actual occurrence of the forecasted developments. The SEC generally permits mining companies in their filings with the SEC to disclose only those mineral deposits that the company can economically and legally extract. Certain measures in this presentation, including “deposits", would not generally be permitted in an SEC filing. The material denoted by such terms is not proven or probable Reserves as such terms are used in the SEC's Industry Guide 7, and there can be no assurance that BHP Billiton will be able to convert such material to proven or probable Reserves or extract such material economically. BHP Billiton urges investors to refer to its Annual Report on Form 20-F for the fiscal year ended June 30, 2007, for its most recent statement of mineral Reserves calculated in accordance with Industry Guide 7. Information Relating to the US Offer for Rio Tinto plc BHP Billiton plans to register the offer and sale of securities it would issue to Rio Tinto plc US shareholders and Rio Tinto plc ADS holders by filing with the SEC a Registration Statement (the “Registration Statement”), which will contain a prospectus (the “Prospectus”), as well as other relevant materials. No such materials have yet been filed. This communication is not a substitute for any Registration Statement or Prospectus that BHP Billiton may file with the SEC. U.S. INVESTORS AND U.S. HOLDERS OF RIO TINTO PLC SECURITIES AND ALL HOLDERS OF RIO TINTO PLC ADSs ARE URGED TO READ ANY REGISTRATION STATEMENT, PROSPECTUS AND ANY OTHER DOCUMENTS MADE AVAILABLE TO THEM AND/OR FILED WITH THE SEC REGARDING THE POTENTIAL TRANSACTION, AS WELL AS ANY AMENDMENTS AND SUPPLEMENTS TO THOSE DOCUMENTS, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders will be able to obtain a free copy of the Registration Statement and the Prospectus as well as other relevant documents filed with the SEC at the SEC's website (http://www.sec.gov), once such documents are filed with the SEC. Copies of such documents may also be obtained from BHP Billiton without charge, once they are filed with the SEC.

Page 3 Page 3 Page 3 Disclaimer (Continued) Information for US Holders of Rio Tinto Limited Shares BHP Billiton Limited is not required to, and does not plan to, prepare and file with the SEC a registration statement in respect of the Rio Tinto Limited Offer. Accordingly, Rio Tinto Limited shareholders should carefully consider the following: The Rio Tinto Limited Offer will be an exchange offer made for the securities of a foreign company. Such offer is subject to disclosure requirements of a foreign country that are different from those of the United States. Financial statements included in the document will be prepared in accordance with foreign accounting standards that may not be comparable to the financial statements of United States companies. Information Relating to the US Offer for Rio Tinto plc and the Rio Tinto Limited Offer for Rio Tinto shareholders located in the US It may be difficult for you to enforce your rights and any claim you may have arising under the U.S. federal securities laws, since the issuers are located in a foreign country, and some or all of their officers and directors may be residents of foreign countries. You may not be able to sue a foreign company or its officers or directors in a foreign court for violations of the U.S. securities laws. It may be difficult to compel a foreign company and its affiliates to subject themselves to a U.S. court's judgment. You should be aware that BHP Billiton may purchase securities of either Rio Tinto plc or Rio Tinto Limited otherwise than under the exchange offer, such as in open market or privately negotiated purchases. References in this presentation to “$” are to United States dollars unless otherwise specified.

Page 4 Agenda • Olympic Dam is a world class and superior resource • Strong nuclear demand growth prospects • Nuclear key to address climate change • Carbon price rewrites nuclear economics • China impact in the uranium industry

Page 5 0 20 40 60 80 100 120 140 160 Page 5 Olympic Dam: A world class resource mt Copper kt U3O 8 moz Au ~1100 1050 1000 Sources:  Company Annual Reports and press releases (as at 30-Sep-2007). International Atomic Energy Agency Note: Witwatersrand figure is BHP Billiton estimate and is approximate only a) Based on reported resource “inventory”. 0 500 1000 1500 2000 2500 The largest uranium deposit in the world 4th largest copper deposit in the world 0 50 100 150 200 250 5th largest gold deposit in the world

Page 6 Page 6 Olympic Dam: A world class resource Notes: a) 100% of production shown. Split of bubble 55% Rio Tinto, 45% BHP Billiton. b) Bubble size reflects Rio Tinto’s current 19.9% exposure to Oyu Tolgoi. Rio Tinto has options to increase its ownership interest to 46.6%. Olympic Dam relative to Rio Tinto’s undeveloped copper projects La Granja Resolution(a) Oyu Tolgoi(b) Pebble Olympic Dam 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 50 100 150 200 250 Contained copper equivalent mineralisation - Mt Solid bubble = Existing production Transparent bubble = Targeted annual production Note: Bubble size reflects forecast annual copper capacity

Page 7 Agenda • Olympic Dam is a world class and superior resource • Strong nuclear demand growth prospects • Nuclear key to address climate change • Carbon price rewrites nuclear economics • China impact in the uranium industry

Page 8 0 2,500 5,000 7,500 10,000 12,500 15,000 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 2030 World Primary Energy Use (million tonnes of oil equivalent) * At a hypothetical world average growth rate of 1% p.a. Source of data: 1965-2006: BP Statistical Review of World Energy; bntoe = billion tonnes oil equivalent 1900-1965: Derived from Maddison, UK Select Committee on Economic Affairs. 400 bntoe = 600 billion tonnes of hard coal The world is well on its way to consuming as much energy in the next 25 years as it has consumed throughout modern history OECD FSU Emerging Markets 1900-2006 Total = 400 bntoe 2007-2030 Total = 300 bntoe*

Page 9 Primary energy consumption is strongly correlated to economic development Source: World Bank, Government Statistics for Taiwan, BP Statistical Review of World Energy (2007) Primary energy use (tonnes of oil equiv/capita) 0 2 4 6 8 10 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 GDP/Capita (Jan 2008 Constant US Dollars) China Germany India Japan Korea, Rep. United States Taiwan

Page 10 China’s annual power output is growing at a rate equivalent to a major European country 426 400 0 500 1000 1500 2000 2500 3000 3500 1999 2000 2001 2002 2003 2004 2005 2006 2007 Power output added from previous year UK’s total power output today China’s Growing Power Output (in billion kWh)

Energy Issues? • Power generation and distribution • Energy efficiency and intensity • Urban environment and transport • Emissions

Page 12 Notes: a) Source: International Nucelar Safety Centre at ANL, Aug-2005 (www.insc.anl.gov/pwrmaps/world_map.pdf). b) Source: World Nuclear Association (www.world-nuclear.org/info.reactors.html), 17-Oct-2007. Page 12 Olympic Dam: Exposure to strong forecast nuclear demand growth – especially in the East Under construction (reactors) – 33 reactors (b) Proposed (reactors) – > 222 reactors (b) Planned (reactors) – > 94 reactors (b) Operational (power plants) – 439 reactors (b) Existing operational power plants (a)

Page 13 Notes: a) Location of reactors that are planned, under construction, and proposed is by country, but does not necessarily show their exact geographical location in a country. b) Source: International Nucelar Safety Centre at ANL, Aug-2005 (www.insc.anl.gov/pwrmaps/world_map.pdf). c) Source: World Nuclear Association (www.world-nuclear.org/info.reactors.html), 17-Oct-2007. Page 13 Olympic Dam: Exposure to strong forecast nuclear demand growth – especially in the East Under construction (reactors) – 33 reactors (c) Proposed (reactors) – > 222 reactors (c) Planned (reactors) – > 94 reactors (c) Operational (power plants) – 439 reactors (c) Existing operational power plants and future development of nuclear power reactors (a),(b)

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Page 16 Agenda • Olympic Dam is a world class and superior resource • Strong nuclear demand growth prospects • Nuclear key to address climate change • Carbon price rewrites nuclear economics • China impact in the uranium industry

Page 17 Carbon price rewrites nuclear economics Relative economics at no carbon cost 0 50 100 150 Nuclear Coal Gas Relative economics @ $30/t CO2 0 50 100 150 Nuclear Coal Gas Relative economics @ $50/ t CO2 0 50 100 150 Nuclear Coal Gas Sources:  WNA, UIC/AUA, CERA, OECD/IEA, US DOE, UK govt, CRU group • Nuclear power is competitive with other generation technologies at current prices • At carbon cost of $50/ t CO2, the carbon cost of coal fired generation is on par with the capital cost for nuclear • These are indicators for the “western” world. Developments in other industries, such as Alumina, have proven that the Chinese are capable of substantially decreasing both lead-time and capital cost on construction, significantly reducing the issue of the substantial capital cost of nuclear power $/MWh $/MWh $/MWh • Capital cost • O&M cost • Fuel cost • Carbon cost • Decommissioning

Page 18 *Including wind, biomass, oil, etc ** Include power sector and non-power sector thermal coal use (excluding coking coal) Source:NDRC power plant project database; Interviews; expert interviews; BHP Billiton; team analysis Uranium What if China goes nuclear? 1,532 2,054 1,532 2,054 12% 4% 26% 33% GW Installed % Nuclear Traditional China 2030 electricity demand Nuclear China electricity demand  2030 – what if 42 17 150 88 Ktpa U308 Case B, rapid move away from energy intensity Case A, low gains in energy efficiency 337 676 251 346 426 262 400 680 Case B, rapid move away from energy intensity Case A, low gains in energy efficiency 262 555 1,281 251 346 426 182 75 Coal Hydro Gas Other

Page 19 Impact of carbon emissions Global green house gas emissions growth and abatement requirements (GT CO2 e*) 4.8 6.7 38.5 2005 China 2.8 US 0.9 EU 8.6 RoW 45.3 59.3 2030 23** Abatement requirement 2030 including abatement RoW EU US China +155% 21.5 * Total emissions, including green house gas emissions from non-power sectors ** Total global abatement requirement based on need to minimize global warming to 2-3° Celsius Source: WRI; IEA; Team analysis 41 China 13 US 4 EU 41 RoW Growth 2005-2030 100% = 21 GT DSM 2.4 Other** 1.5 China Nuclear 0.8 – 4.5 CCS 2.7 Approach Impact GT -12 -24 3 15 Cost $/tCO2e GT CO2 Ave = 7.5GT CO2e emission acceptable from China in 2030 (+36% Higher than 2005 level) 4.5** Australia 0.5 8.5 5.5 14.0 31.3

Page 20 China has been predictable in re-writing capital intensity and delivery 60-66 Months US$3000- US$5000/t installed capacity 40 Months, Greenfields US$1000- 1300/t installed capacity Detailed engineering through commissioning Copper smelters 40 Months + 400kt/yr alumina refinery – construction time 10 months Kaiman alumina 40 Months + 400kt/yr alumina refinery – construction time 14 months Jinbei Alumina 40 Months + 800kt/yr alumina refinery – construction time 10 months East Hope Alumina 40 Months + 10x 300mw power stations and 3500kt/yr alumina refinery – construction time 10 months Alumina refinery Shangdong province Western Benchmark China

Page 21 Greenfields Olympic Dam well positioned to meet energy demand Expand open pit add Greenfield concentrator and hydrometallurgy circuits and expand smelter capacity Further expansion of open pit, build new concentrator and hydrometallurgy circuit Sell excess concentrate Stages CONCEPTUAL Output Cu (ktpa) U30 8 (ktpa) Au (kozpa) 540 14 600 730 19 800 Further growth opportunities Add Hydrometallurgy circuit 350 9 400 Brownfields Optimise current configuration Develop open pit production build Greenfield concentrator sell excess concentrate Current 350 4.5 400 200 4.5 120 180 4 100 +3Mtpa +2Mtpa Mining Concentrating & Hydrometallurgy Smelting 5 4 + 2 3 Notes: Unless specified all capacities are in tonnes of ore. Actual timing of Underground phase out is not yet determined +2Mtpa (100ktpa con) +20Mtpa (250ktpa con) 1.1 1 2 0 0 10Mtpa 9Mtpa 0Mtpa +20Mtpa +20Mtpa +20Mtpa +20Mtpa 20Mtpa 72Mtpa 52Mtpa 10Mtpa (500ktpa con) +20Mtpa (800ktpa con) +20Mtpa (800ktpa con)

Page 22 Mining investment cycle: Escondida case study Low price cycles High price cycles Discovery Discovery 0.60 1.10 1.60 2.10 2.60 3.10 3.60 0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000 1,600,000 Grassroots Exploration Resource Definition Feasibility & Financing Construction Operation and additional growth options

Page 23 Page 23 Page 23 The world at night