UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                               -------------------
                                    FORM 8-K
                              --------------------


                                 CURRENT REPORT

     PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934


       Date of Report (Date of earliest event reported): October 14, 2005

                U.S. BORAX INC. 401(K) PLAN FOR HOURLY EMPLOYEES
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             (Exact name of registrant as specified in its charter)

     Delaware                       001-10533                 98-0047580
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(State of Incorporation)      (Commission File No.)          (I.R.S Employer
                                                             Identification No.)

          Rio Tinto, plc, 6 St. James's Square, London SW1Y 4LD England
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(Address of principal executive offices)                              (Zip Code)


Registrant's Telephone Number, Including Area Code:      +44 207753 2117     
                                                     ------------------------


                                      None
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          (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2 below):

[ ] Written communications pursuant to Rule 425 under the Securities Act
    (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act
    (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the 
    Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the 
    Exchange Act (17 CFR 240.13e-4(c))



                               Page 1 of 6 pages



ITEM 4.01  CHANGES IN REGISTRANT'S CERTIFYING ACCOUNTANT

(a) Previous independent registered public accounting firm

         (i) On October 14, 2005, the administrators of the U.S. Borax 401(k)
Plan for Hourly Employees (the "Plan") dismissed PricewaterhouseCoopers LLP
("PwC") as the Plan's independent registered public accounting firm. PwC was
informed of their dismissal on October 20, 2005. The decision to change the
accounting firm was approved by the Chief of Human Resources of U.S. Borax Inc.
but was not approved by a board of directors or audit committee. The Plan does
not have a board of directors or audit committee.

         (ii) PwC's reports on the Plan's financial statements for the past two
fiscal years ended December 31, 2003 and 2004 did not contain an adverse opinion
or a disclaimer of opinion and were not qualified or modified as to uncertainty,
audit scope, or accounting principle.

         (iii) During the past two fiscal years ended December 31, 2003 and 2004
and through October 14, 2005, there were no disagreements with PwC on any matter
of accounting principles or practices, financial statement disclosure, or
auditing scope or procedure, which disagreements, if not resolved to the
satisfaction of PwC, would have caused PwC to make reference thereto in its
reports on the financial statements for such years.

         (iv) There were no "reportable events" described in Item 304(a)(1)(v)
of Regulation S-K with respect to the fiscal years ended December 31, 2003 and
2004 and through October 14, 2005.

         (v) The Plan has requested PwC to furnish the Plan with a letter
addressed to the Securities and Exchange Commission stating whether PwC agrees
with the above statements. A copy of PwC's letter, dated October 28, 2005, is
filed as Exhibit 16.1 to this Form 8-K.

(b) New independent registered public accounting firm

         (i) On October 14, 2005, the administrators of the Plan appointed
Tanner LC ("Tanner") as the Plan's independent registered public accounting firm
for the year ending December 31, 2005. During the Plan's two most recent fiscal
years and through October 14, 2005 neither the Plan nor anyone acting on its
behalf consulted Tanner regarding (1) either the application of accounting
principles to a specified transaction, either completed or proposed, or the type
of audit opinion that might be rendered on the Plan's financial statements or
(2) any matter that was either the subject of a disagreement, as that term is
defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions to
Item 304 of Regulation S-K, or a "reportable event" as described in Item
304(a)(1)(v) of Regulation S-K of the Securities and Exchange Commission.



                               Page 2 of 6 pages


(c)      Exhibits

16.1     Letter from PricewaterhouseCoopers LLP to the Securities and 
         Exchange Commission regarding change in certifying accountant.






                               Page 3 of 6 pages



                                    SIGNATURE

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this Report to be signed on its behalf by the
undersigned, thereunto duly authorized.


                               U.S. BORAX INC. 401(K) PLAN FOR HOURLY EMPLOYEES


                               By: /s/ Steven B. Saperstein
                                   ---------------------------------------------
                                   Name:  Steven B. Saperstein
                                   Title: Chief of Human Resources of 
                                          U.S. Borax Inc.


Date: October 28, 2005





                               Page 4 of 6 pages


                               TABLE OF CONTENTS


                                  EXHIBIT INDEX

16.1     Letter from PricewaterhouseCoopers LLP to the Securities and 
         Exchange Commission regarding change in certifying accountant.




                               Page 5 of 6 pages