SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C. 20549

                               SCHEDULE 14D-1
                              Amendment No. 18
                           Tender Offer Statement
    Pursuant to Section 14(d)(1) of the Securities Exchange Act of 1934

                         Rental Service Corporation
                         (Name of Subject Company)

                         UR Acquisition Corporation
                            United Rentals, Inc.
                                 (Bidders)

                   Common Stock, par value $.01 per share
                       (Title of Class of Securities)

                                76009V 10 2
                   (CUSIP Number of Class of Securities)

                            United Rentals, Inc.
                         Four Greenwich Office Park
                            Greenwich, CT 06830
                          Attn.: Bradley S. Jacobs
                         Chairman of the Board and
                          Chief Executive Officer
                          Telephone:(203) 622-3131
                          Facsimile:(203) 622-6080
        (Name, Address and Telephone Number of Person authorized to
          Receive Notices and Communications on Behalf of Bidders)

                                  Copy to:

                           Milton G. Strom, Esq.
                  Skadden, Arps, Slate, Meagher & Flom LLP
                              919 Third Avenue
                          New York, New York 10022
                         Telephone: (212) 735-3000
                         Facsimile: (212) 735-2000





      UR Acquisition Corporation, a Delaware corporation (the "Purchaser")
and a wholly owned subsidiary of United Rentals, Inc., a Delaware
corporation ("Parent"), and Parent hereby amend and supplement their Tender
Offer Statement on Schedule 14D-1 (as amended from time to time, the
"Schedule 14D-1"), filed with the Securities and Exchange Commission (the
"Commission") on April 5, 1999, with respect to the Purchaser's offer to
purchase all of the shares of common stock, par value $0.01 per share
(collectively with the associated preferred stock purchase rights (the
"Rights") issued pursuant to the Rights Agreement, dated as of April 16,
1999 (the "Rights Agreement"), between Rental Service Corporation and
ChaseMellon Shareholder Services, L.L.C., the "Shares"), of Rental Service
Corporation, a Delaware corporation (the "Company"), at a price of $22.75
per Share, net to the seller in cash (such price, or such higher price per
Share as may be paid in the Offer, the "Offer Price"), upon the terms and
subject to the conditions set forth in the Offer to Purchase and in the
related Letter of Transmittal (which, as amended from time to time,
together constitute the "Offer"). Unless otherwise indicated herein, each
capitalized term used but not defined herein shall have the meaning
ascribed to such term in the Schedule 14D-1 or in the Offer to Purchase
referred to therein.


Item 10.  Additional Information.

      The information set forth in Item 10(a) of the Schedule 14D-1 is
hereby amended and supplemented by the following information:

      On May 24, 1999, a representative of Goldman, Sachs & Co. ("Goldman,
Sachs"), financial advisor to Parent, attempted to contact Morgan Stanley &
Co. Incorporated ("Morgan Stanley"), financial advisor to the Company, by
telephone on behalf of Parent. On May 25, 1999, a representative of Morgan
Stanley responded to such contact and was informed by the representative of
Goldman, Sachs that Parent would be interested in participating in any
process that the Company may conduct as a result of the review and
evaluation of the Company's strategic alternatives being conducted by its
financial advisors which was disclosed in the Company's press release
issued on May 21, 1999.



                                 SIGNATURE

      After due inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete
and correct.

                                      UR ACQUISITION CORPORATION

                                      By:  /S/ JOHN N. MILNE
                                           -------------------------
                                           Name:  John N. Milne
                                           Title: President


                                      UNITED RENTALS, INC.


                                      By:  /S/ BRADLEY S. JACOBS
                                           -----------------------------
                                           Name:  Bradley S. Jacobs
                                           Title: Chairman and Chief Executive
                                                  Officer


Date: May 26, 1999