UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549



                                  SCHEDULE 13G

                   Under the Securities Exchange Act of 1934*

                               (Amendment No. __)

                         Core-Mark Holding Company, Inc.
                         -------------------------------
                                (Name of Issuer)

                     Common Stock, par value $0.01 per share
                     ---------------------------------------
                         (Title of Class of Securities)

                                    218681104
                                    ---------
                                 (CUSIP Number)

                                December 14, 2005
                                -----------------
             (Date of Event Which Requires Filing of this Statement)

     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:

                                [ ] Rule 13d-1(b)
                                [X] Rule 13d-1(c)
                                [ ] Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 (the "Act") or otherwise subject to the liabilities of that section of the
Act but shall be subject to all other provisions of the Act (however, see the
Notes).





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

CUSIP No.  218681104                      13G               Page  2 of 10 Pages
----------------------------                                --------------------

---------- ---------------------------------------------------------------------
1          NAME OF REPORTING PERSON
           S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Third Point LLC
---------- ---------------------------------------------------------------------
2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                    (a) [ ]
                                                                    (b) [X}
---------- ---------------------------------------------------------------------
3          SEC USE ONLY

---------- ---------------------------------------------------------------------
4          CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------------------------------------------------------------------
                     5      SOLE VOTING POWER

                            0
                     ------ ----------------------------------------------------
     NUMBER OF       6      SHARED VOTING POWER
      SHARES
   BENEFICIALLY             973,095
     OWNED BY        ------ ----------------------------------------------------
       EACH          7      SOLE DISPOSITIVE POWER
     REPORTING
      PERSON                0
       WITH
                     ------ ----------------------------------------------------
                     8      SHARED DISPOSITIVE POWER

                            973,095
---------- ---------------------------------------------------------------------
9          AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           973,095
---------- ---------------------------------------------------------------------
10         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

           N/A
---------- ---------------------------------------------------------------------
11         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

           9.9%
---------- ---------------------------------------------------------------------
12         TYPE OF REPORTING PERSON

           OO
---------- ---------------------------------------------------------------------





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

CUSIP No.  218681104                      13G               Page  3 of 10 Pages
----------------------------                                --------------------

---------- ---------------------------------------------------------------------
1          NAME OF REPORTING PERSON
           S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Daniel S. Loeb
---------- ---------------------------------------------------------------------
2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                    (a) [ ]
                                                                    (b) [X}
---------- ---------------------------------------------------------------------
3          SEC USE ONLY

---------- ---------------------------------------------------------------------
4          CITIZENSHIP OR PLACE OF ORGANIZATION

           United States
--------------------------------------------------------------------------------
                     5      SOLE VOTING POWER

                            0
                     ------ ----------------------------------------------------
     NUMBER OF       6      SHARED VOTING POWER
      SHARES
   BENEFICIALLY             973,095
     OWNED BY        ------ ----------------------------------------------------
       EACH          7      SOLE DISPOSITIVE POWER
     REPORTING
      PERSON                0
       WITH
                     ------ ----------------------------------------------------
                     8      SHARED DISPOSITIVE POWER

                            973,095
---------- ---------------------------------------------------------------------
9          AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           973,095
---------- ---------------------------------------------------------------------
10         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

           N/A
---------- ---------------------------------------------------------------------
11         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

           9.9%
---------- ---------------------------------------------------------------------
12         TYPE OF REPORTING PERSON

           IN
---------- ---------------------------------------------------------------------




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

CUSIP No.  218681104                      13G               Page  4 of 10 Pages
----------------------------                                --------------------

---------- ---------------------------------------------------------------------
1          NAME OF REPORTING PERSON
           S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Third Point Offshore Fund, Ltd.
---------- ---------------------------------------------------------------------
2          CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                    (a) [ ]
                                                                    (b) [X}
---------- ---------------------------------------------------------------------
3          SEC USE ONLY

---------- ---------------------------------------------------------------------
4          CITIZENSHIP OR PLACE OF ORGANIZATION

           Cayman Islands
--------------------------------------------------------------------------------
                     5      SOLE VOTING POWER

                            0
                     ------ ----------------------------------------------------
     NUMBER OF       6      SHARED VOTING POWER
      SHARES
   BENEFICIALLY             602,464
     OWNED BY        ------ ----------------------------------------------------
       EACH          7      SOLE DISPOSITIVE POWER
     REPORTING
      PERSON                0
       WITH
                     ------ ----------------------------------------------------
                     8      SHARED DISPOSITIVE POWER

                             602,464
---------- ---------------------------------------------------------------------
9          AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            602,464
---------- ---------------------------------------------------------------------
10         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

           N/A
---------- ---------------------------------------------------------------------
11         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

           6.1%
---------- ---------------------------------------------------------------------
12         TYPE OF REPORTING PERSON

           OO
---------- ---------------------------------------------------------------------

                                      -4-



Item 1(a):  Name of Issuer:
---------   --------------

The name of the issuer is Core-Mark Holding Company, Inc., a corporation
organized under the laws of the State of Delaware (the "Company").

Item 1(b):  Address of Issuer's Principal Executive Offices:
---------   -----------------------------------------------

The Company's principal executive office is located at 395 Oyster Point
Boulevard, Suite 415, South San Francisco, California 94080.

Item 2(a):  Name of Person Filing:
---------   ---------------------

This Schedule 13G is filed by:

    (i)   Third Point LLC, a Delaware limited liability company (the "Management
          Company"), which serves as investment manager or adviser to a variety
          of hedge funds and managed accounts (such funds and accounts,
          collectively, the "Funds"), with respect to shares of Common Stock (as
          defined in Item 2(d)) directly owned by the Funds; and

    (ii)  Mr. Daniel S. Loeb ("Mr. Loeb"), who is the Chief Executive Officer of
          the Management Company and controls its business activities, with
          respect to shares of Common Stock indirectly beneficially owned by Mr.
          Loeb by virtue of such position.

    (iii) Third Point Offshore Fund, Ltd., a Cayman Islands limited liability
          exempted company (the "Offshore Fund") which invests and trades in
          securities, with respect to shares of Common Stock directly
          beneficially owned by it.

The Management Company, Mr. Loeb and the Offshore Fund are hereinafter sometimes
collectively referred to as the "Reporting Persons." Any disclosures herein with
respect to persons other than the Reporting Persons are made on information and
belief after making inquiry to the appropriate party.

Item 2(b):  Address of Principal Business Office or, if None, Residence:
---------   -----------------------------------------------------------

The address of the principal business office of the Management Company and Mr.
Loeb is 390 Park Avenue, 18th Floor, New York, New York 10022. The address of
the principal business office of the Offshore Fund is c/o Walkers SPV Limited,
Walker House, Mary Street, P.O. Box 908GT, George Town, Grand Cayman, Cayman
Islands, British West Indies.

Item 2(c):  Citizenship:
---------   -----------

The Management Company is organized as a limited liability company under the
laws of the State of Delaware. Mr. Loeb is a United States citizen. The Offshore
Fund is organized as a limited liability exempted company under the laws of the
Cayman Islands.

                                      -5-



Item 2(d):  Title of Class of Securities:
---------   ----------------------------

Common Stock, par value $0.01 ("Common Stock").

Item 2(e):  CUSIP Number:
---------   ------------

218681104

Item 3:     If this statement is filed pursuant to Rules 13d-1(b) or 13d-2(b)or
------      -------------------------------------------------------------------
            (c), check whether the person filing is a:
            -----------------------------------------
          A.   [ ] Broker or dealer registered under Section 15 of the Act,
          B.   [ ] Bank as defined in Section 3(a)(6) of the Act,
          C.   [ ] Insurance Company as defined in Section 3(a)(19) of the Act,
          D.   [ ] Investment Company registered under Section 8 of the
                   Investment Company Act of 1940,
          E.   [ ] Investment Adviser in accordance with Rule 13d-1
                   (b)(1)(ii)(E),
          F.   [ ] Employee Benefit Plan or Endowment Fund in accordance with
                   13d-1 (b)(1)(ii)(F),
          G.   [ ] Parent Holding Company or control person in accordance with
                   Rule 13d-1 (b)(1)(ii)(G),
          H.   [ ] Savings Association as defined in Section 3(b) of the Federal
                   Deposit Insurance Act,
          I.   [ ] Church Plan that is excluded from the definition of an
                   investment company under Section 3(c)(14) of the Investment
                   Company Act of 1940,
          J.   [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).


Item 4:     Ownership:
------      ---------

The beneficial ownership of Common Stock by the Reporting Persons, as of the
date of this Schedule 13G, is as follows:

     A. Third Point LLC
        ---------------
          (a)  Amount beneficially owned: 973,095
          (b) Percent of class: 9.9%. The percentages used herein and in the
     rest of this Schedule 13G are calculated based upon the 9,808,542 shares of
     Common Stock issued and outstanding as of October 31, 2005, as reflected in
     the Company's Quarterly Report on Form 10-Q for the quarterly period ended
     September 30, 2005.
          (c)  Number of shares as to which such person has:
               (i)  Sole power to vote or direct the vote: 0
               (ii) Shared power to vote or direct the vote: 973,095
               (iii) Sole power to dispose or direct the disposition: 0
               (iv) Shared power to dispose or direct the disposition: 973,095

                                      -6-



     B. Daniel S. Loeb
        --------------
          (a) Amount beneficially owned: 973,095
          (b) Percent of class: 9.9%.
          (c) Number of shares as to which such person has:
               (i)   Sole power to vote or direct the vote: 0
               (ii)  Shared power to vote or direct the vote: 973,095
               (iii) Sole power to dispose or direct the disposition: 0
               (iv)  Shared power to dispose or direct the disposition: 973,095

     C. Third Point Offshore Fund, Ltd.
        ------------------------------
          (a) Amount beneficially owned: 602,464
          (b) Percent of class: 6.1%.
          (c) Number of shares as to which such person has:
               (i)   Sole power to vote or direct the vote: 0
               (ii)  Shared power to vote or direct the vote: 602,464
               (iii) Sole power to dispose or direct the disposition: 0
               (iv)  Shared power to dispose or direct the disposition: 602,464

The Management Company and Mr. Loeb were the beneficial owners of 924,043 shares
of Common Stock before the Company's registration statement on Form 10 became
effective under the Act. The Offshore Fund was the beneficial owner of 571,800
shares of Common Stock before the Company's registration statement on Form 10
became effective under the Act.

Item 5:     Ownership of Five Percent or Less of a Class:
------      --------------------------------------------

If this statement is being filed to report the fact that as of the date hereof
the reporting person has ceased to be the beneficial owner of more than five
percent of the class of securities, check the following: [ ]

Item 6:     Ownership of More than Five Percent on Behalf of Another Person:
------      ---------------------------------------------------------------

Other than as set forth herein, no other person has the right to receive or the
power to direct the receipt of dividends from, or proceeds from the sale of, in
excess of 5% of the total outstanding Common Stock.

Item 7:     Identification and Classification of the Subsidiary Which Acquired
------      ------------------------------------------------------------------
            the Security Being Reported on by the Parent Holding  Company:
            -------------------------------------------------------------

Not applicable.

Item 8:     Identification and Classification of Members of the Group:
------      ---------------------------------------------------------

Not applicable.


                                      -7-



Item 9:     Notice of Dissolution of Group:
------      ------------------------------

Not applicable.

Item 10:    Certification:
-------     -------------

Each of the Reporting Persons hereby makes the following certification:

     By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were not acquired and are not held for the
purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.

                                      -8-



                                    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.


Dated: February 10, 2006



                                    THIRD POINT LLC


                                    By:  /s/ Daniel S. Loeb
                                         ---------------------------------------
                                         Name: Daniel S. Loeb
                                         Title: Chief Executive Officer


                                    THIRD POINT OFFSHORE FUND, LTD.


                                     By:  /s/ Daniel S. Loeb
                                         ---------------------------------------
                                         Name: Daniel S. Loeb
                                         Title: Director



                                     /s/ Daniel S. Loeb
                                     -------------------------------------------
                                     Daniel S. Loeb



                 [SIGNATURE PAGE TO SCHEDULE 13G WITH RESPECT TO
                        CORE-MARK HOLDING COMPANY, INC.]





                                  EXHIBIT INDEX
                                  -------------


Exhibit 1:  Joint Filing Agreement, dated February 10, 2006, by and between
            Third Point LLC, Daniel S. Loeb and Third Point Offshore Fund, Ltd.