<SUBMISSION>
<ACCESSION-NUMBER>0000950123-01-001517
<TYPE>SC 14D9/A
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20010215
<SUBJECT-COMPANY>
<COMPANY-DATA>
<CONFORMED-NAME>ACNIELSEN CORP
<CIK>0001019878
<ASSIGNED-SIC>8700
<IRS-NUMBER>061454128
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC 14D9/A
<ACT>34
<FILE-NUMBER>005-47591
<FILM-NUMBER>1547893
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>177 BROAD STREET
<CITY>STAMFORD
<STATE>CT
<ZIP>06901
<PHONE>2038344200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>177 BROAD ST
<CITY>STAMFORD
<STATE>CT
<ZIP>06901
</MAIL-ADDRESS>
</SUBJECT-COMPANY>
<FILED-BY>
<COMPANY-DATA>
<CONFORMED-NAME>ACNIELSEN CORP
<CIK>0001019878
<ASSIGNED-SIC>8700
<IRS-NUMBER>061454128
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC 14D9/A
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>177 BROAD STREET
<CITY>STAMFORD
<STATE>CT
<ZIP>06901
<PHONE>2038344200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>177 BROAD ST
<CITY>STAMFORD
<STATE>CT
<ZIP>06901
</MAIL-ADDRESS>
</FILED-BY>
<DOCUMENT>
<TYPE>SC 14D9/A
<SEQUENCE>1
<FILENAME>y45113a6sc14d9a.txt
<DESCRIPTION>AMENDMENT NO. 6 TO SCHEUDLE 14D-9
<TEXT>

<PAGE>   1

   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 15, 2001
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                            ------------------------

                                 SCHEDULE 14D-9

                                 (RULE 14d-101)
                     SOLICITATION/RECOMMENDATION STATEMENT
                             UNDER SECTION 14(d)(4)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                               (AMENDMENT NO. 6)

                            ------------------------

                             ACNIELSEN CORPORATION
                           (NAME OF SUBJECT COMPANY)

                             ACNIELSEN CORPORATION
                      (NAME OF PERSON(S) FILING STATEMENT)

                    COMMON STOCK, PAR VALUE $0.01 PER SHARE
           (INCLUDING THE ASSOCIATED PREFERRED SHARE PURCHASE RIGHTS)
                         (TITLE OF CLASS OF SECURITIES)

                                   004833109
                     (CUSIP NUMBER OF CLASS OF SECURITIES)

                             EARL H. DOPPELT, ESQ.
                            EXECUTIVE VICE PRESIDENT
                              AND GENERAL COUNSEL
                             ACNIELSEN CORPORATION
                                177 BROAD STREET
                          STAMFORD, CONNECTICUT 06901
                                 (203) 961-3000
                 (NAME, ADDRESS AND TELEPHONE NUMBER OF PERSON
               AUTHORIZED TO RECEIVE NOTICE AND COMMUNICATIONS ON
                   BEHALF OF THE PERSON(S) FILING STATEMENT)

                                    COPY TO:

                               RICHARD A. GARVEY
                                 JOHN G. FINLEY
                           SIMPSON THACHER & BARTLETT
                              425 LEXINGTON AVENUE
                         NEW YORK, NEW YORK 10017-3954
                                 (212) 455-2000

Check the box if the filing relates solely to preliminary communication made
before the commencement of a tender offer.  [ ]

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>   2

     This Amendment No. 6 (the "Amendment") amends and supplements the Schedule
14D-9 filed with the Securities and Exchange Commission on December 22, 2000
(the "14D-9"), as amended by Amendments No. 1, No. 2, No. 3, No 4 and No. 5 to
the 14D-9 filed on January 16, 18 and 24 and February 7 and 13, 2001,
respectively, by ACNielsen Corporation (the "Company"), relating to the tender
offer by Artist Acquisition, Inc. ("Purchaser"), a Delaware corporation and a
wholly owned subsidiary of VNU N.V. ("Parent") to purchase all outstanding
shares of common stock, par value $.01 per share (the "Shares"), of the Company,
at a purchase price of $36.75 per Share, net to the seller in cash, upon the
terms and subject to the conditions set forth in the Offer to Purchase dated
December 22, 2000 (the "Offer to Purchase") and the related Letter of
Transmittal (which, together with any supplements or amendments thereto,
collectively constitute the "Offer"). The Offer is described in a Tender Offer
Statement on Schedule TO (as amended or supplemented from time to time, the
"Schedule TO"), filed by the Purchaser with the Securities and Exchange
Commission on December 22, 2000.

ITEM 8.  ADDITIONAL INFORMATION

     Item 8(b) of the 14D-9 is hereby amended and supplemented by the following:

     At 12:00 midnight, New York City time, on February 14, 2001, the Offer
expired. Based on a preliminary count, approximately 56,948,651 Shares were
tendered pursuant to the Offer, of which 2,246,242 were tendered pursuant to
notices of guaranteed delivery. Such Shares constituted approximately 96% of the
outstanding Shares. On February 15, 2001, effective as of 12:01 a.m., New York
City time, all Shares validly tendered and not withdrawn prior to the expiration
of the Offer were accepted for payment. A copy of the press release announcing
the expiration of the Offer and the acceptance of validly tendered Shares is
attached hereto as Exhibit (a)(9), which is incorporated by reference herein.
<PAGE>   3

ITEM 9.  EXHIBITS.

     The following exhibit is filed herewith:

<TABLE>
<C>           <S>
      (a)(9)  Press Release, dated February 15, 2001 (incorporated by
              reference to Exhibit (a)(5)(vi) to the Final Amendment to
              the Schedule TO filed on February 15, 2001.)
</TABLE>

                                   SIGNATURE

     After reasonable 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.

                                          ACNIELSEN CORPORATION

                                          By: /s/ Earl H. Doppelt
                                            ------------------------------------
                                            Name: Earl H. Doppelt
                                            Title: Executive Vice President and
                                              General Counsel

Dated: February 15, 2001
<PAGE>   4

                                 EXHIBIT INDEX
<TABLE>
<C>           <S>

      (a)(9)  Press Release, dated February 15, 2001 (incorporated by
              reference to Exhibit (a)(5)(vi)to the final Amendment to the
              Schedule TO filed on February 15, 2001).
</TABLE>
</TEXT>
</DOCUMENT>
</SUBMISSION>
