Principal auditors

The remuneration of the Group's principal auditors for audit services and other services, as well as remuneration payable to other accounting firms, has been set out in note 41 to the 2006 Financial statements.

Rio Tinto has adopted policies designed to uphold the independence of the Group's principal auditors by prohibiting their engagement to provide a range of accounting and other professional services that might compromise their appointment as independent auditors. The engagement of the Group's principal auditors to provide statutory audit services, certain other assurance services, tax services and some other specific services are pre-approved annually by the Audit committee. Each engagement of the Group's principal auditors to provide other permitted services is subject to the specific approval of the Audit committee or its chairman.

Prior to the commencement of each financial year, the Group's finance director submits to the Audit committee a schedule of the types of services that are expected to be performed during the following year for its approval. The Audit committee may impose a US dollar limit on the total value of other permitted services that can be provided. Any non audit service provided by the Group's principal auditors, where the expected fee exceeds a pre-determined level, must be subject to the Group's normal tender procedures. However, in exceptional circumstances the finance director is authorised to engage the Group's principal auditors to provide such services without going to tender, but if the fees are expected to exceed US$250,000 then the chairman of the Audit committee must approve the engagement.

The Audit committee has adopted policies for the pre-approval of permitted services provided by the Group's principal auditors. These are regularly reviewed by the committee. Engagements for services provided by the Group's principal auditors since the adoption of these policies were either within the pre-approval policies or approved by the Audit committee.