Energy Resources of Australia

Rio Tinto PLC
27 October 2005

Rio Tinto's 68.4 per cent owned subsidiary, Energy Resources of Australia (ERA),
issued the following news release in Australia today.





Increase in Ranger mine's reserves and resources





•         Total reserves increased by 6,285 tonnes contained uranium oxide.



•         Total resources increased by 14,923 tonnes contained uranium oxide.



•         These increases result from a reduction in the cut-off grade from 0.12
          per cent to 0.08 per cent uranium oxide.



•         The additional reserves will be processed between 2011 and 2014,
          adding three years to the predicted operational life of Ranger.





Recent increases in the market price of uranium oxide have warranted a review of
the cut off grade for processing Ranger ore (the cut off grade is the level down
to which it is deemed to be economic to process ore). For at least the last ten
years, ERA has deemed the economic cut off grade to be 0.12 per cent uranium
oxide.



ERA expects that this lower grade material will be processed over the period
2011 to 2014, and will result in significantly lower uranium oxide production
during those years. ERA has previously stated that mining at Ranger was expected
to continue until at least 2008 with milling operations continuing until at
least 2011. Mining activities at Ranger are still expected to cease in 2008.





ORE RESERVES AND MINERAL RESOURCES


                                                 As at 30 September 2005             As at 31 December 2004
                                                 Cut-off grade 0.08% U3O8           Cut-off grade 0.12% U3O8
                                             ORE (MT)   GRADE      CONTAINED  ORE (MT)     GRADE       CONTAINED
                                                        (% U3O8)       U3O8,               (% U3O8) U3O8, tonnes
                                                                      tonnes

RANGER ORE RESERVES
Current stockpiles                                9.24     0.152      14,028        6.34       0.20       12,878
Ranger #3 Pit
In-situ ore
Proved                                            4.73      0.25      11,997        4.15       0.29       12,186
Probable                                          8.87      0.22      19,260        7.50       0.25       18,831
Sub total Proved and Probable Reserve            13.60      0.23      31,257       11.65       0.27       31,017

Total Ranger #3
Stockpile, Proved and Probable Reserve           22.84      0.20      45,285       17.99       0.24       43,895
RANGER MINERAL RESOURCES
                                                             IN ADDITION TO THE ABOVE RESERVE

Measured                                        1.47       0.148         2,178   0.80       0.19           1,529
Indicated                                      12.67       0.144        18,219   6.26       0.19          12,020
Sub total Measured and Indicated Resource      14.14       0.144        20,398   7.06       0.19          13,549
Inferred Resource                              16.17       0.140        22,594   7.86       0.18          14,520
Total Resources                                30.31       0.142        42,992  14.92       0.19          28,069




Ranger reserves Reconciliation

Reserves at 31 December 2004                            43,895
Additional Reserves                                      6,285
Depletion of Reserves due to processing                 -4,895
Reserve as at 30 September 2005                         45,285





As required by the Australian Stock Exchange, the above Ranger Mineral Resources
table contains details of other mineralisation that has a reasonable prospect of
being economically extracted in the future but which is not yet classified as
Proven or Probable Reserves. This material is defined as Mineral Resources under
the JORC Code. Estimates of such material are based largely on geological
information with only preliminary consideration of mining, economic and other
factors. While in the judgment of the Competent Person there are realistic
expectations that all or part of the Mineral Resources will eventually become
Proven or Probable Reserves, there is no guarantee that this will occur as the
result depends on further technical and economic studies and prevailing economic
conditions in the future.



Resources are stated as additional to the reserves reported in the table above.



The information in this report that relates to Mineral Resources or Ore Reserves
is based on information compiled by the company's Geologist, Stephen Dinkowitz
and Mining Engineer, Dayle Kenny, who are members of the Australasian Institute
of Mining & Metallurgy and full time employees of the company. Stephen Dinkowitz
and Dayle Kenny have sufficient experience which is relevant to the style of
mineralisation and the type of deposit under consideration, and to the activity
which they are undertaking to qualify as Competent Persons as defined in the
2004 Edition of the 'Australasian Code for Reporting of Exploration Results,
Mineral Resources and Ore Reserves'. Stephen Dinkowitz and Dayle Kenny consent
to the inclusion in the report of the matters based on their information in the
form and context in which it appears.





For further information, please contact:


LONDON                                              AUSTRALIA

Media Relations                                     Media Relations
Maria Darby Walker                                  Ian Head
Office:  [phone]                       Office:  [phone]
Mobile: [phone]                        Mobile: [phone]


Investor Relations                                  Investor Relations
Nigel Jones                                         Dave Skinner
Office: [phone]                        Office:  [phone]
Mobile: [phone]                        Mobile: [phone]

David Ovington                                      Susie Creswell
Office:  [phone]                       Office:  [phone]
Mobile: [phone]                        Mobile: [phone]


Website: www.riotinto.com






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