SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D

                   Under the Securities Exchange Act of 1934*

                                (Amendment No. 1)

                   Infinity Property and Casualty Corporation
--------------------------------------------------------------------------------
                                (Name of Issuer)

                           Common Stock, no par value
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    45665Q103
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                      (CUSIP Number of Class of Securities)

                                 Daniel S. Loeb
                                 Third Point LLC
                         360 Madison Avenue, 24th Floor
                               New York, NY 10017
                                 (212) 224-7400
--------------------------------------------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                   Copies to:
                              Jack H. Nusbaum, Esq.
                          Willkie Farr & Gallagher LLP
                               787 Seventh Avenue
                             New York, NY 10019-6099
                                 (212) 728-8000

                                   May 3, 2005
--------------------------------------------------------------------------------
                          (Date of Event which Requires
                            Filing of this Schedule)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of ss.ss. 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the
following box: [ ]

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 240.13d-7 for other
parties to whom copies are to be sent.

* 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
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 ("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).




                                  SCHEDULE 13D

-------------------                                            -----------------
CUSIP No. 45665Q103                                            Page 2 of 9 Pages
-------------------                                            -----------------

----------- --------------------------------------------------------------------
    1       NAME OF REPORTING PERSON
            I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

            Daniel S. Loeb
----------- --------------------------------------------------------------------
    2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP             (a) [ ]
                                                                         (b) [X]

----------- --------------------------------------------------------------------
    3       SEC USE ONLY

----------- --------------------------------------------------------------------
    4       SOURCE OF FUNDS*

            AF
----------- --------------------------------------------------------------------
    5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT
            TO ITEMS 2(d) or 2(e)                                            [ ]

----------- --------------------------------------------------------------------
    6       CITIZENSHIP OR PLACE OF ORGANIZATION

            United States
--------------------- --------- ------------------------------------------------
                         7      SOLE VOTING POWER

                                0
                      --------- ------------------------------------------------
NUMBER OF                8      SHARED VOTING POWER
SHARES
BENEFICIALLY                    920,000
OWNED BY              --------- ------------------------------------------------
EACH                     9      SOLE DISPOSITIVE POWER
REPORTING
PERSON WITH                     0
                      --------- ------------------------------------------------
                         10     SHARED DISPOSITIVE POWER

                                920,000
----------- --------------------------------------------------------------------
    11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON

            920,000
----------- --------------------------------------------------------------------
    12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
            SHARES*                                                          [ ]

----------- --------------------------------------------------------------------
    13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

            4.4%
----------- --------------------------------------------------------------------
    14      TYPE OF REPORTING PERSON*

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




                                  SCHEDULE 13D

-------------------                                            -----------------
CUSIP No. 45665Q103                                            Page 3 of 9 Pages
-------------------                                            -----------------

----------- --------------------------------------------------------------------
    1       NAME OF REPORTING PERSON
            I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

            Third Point LLC                                     I.D. #13-3922602
----------- --------------------------------------------------------------------
    2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP             (a) [ ]
                                                                         (b) [X]

----------- --------------------------------------------------------------------
    3       SEC USE ONLY

----------- --------------------------------------------------------------------
    4       SOURCE OF FUNDS*

            AF
----------- --------------------------------------------------------------------
    5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT
            TO ITEMS 2(d) or 2(e)                                            [ ]

----------- --------------------------------------------------------------------
    6       CITIZENSHIP OR PLACE OF ORGANIZATION

            Delaware
--------------------- --------- ------------------------------------------------
                         7      SOLE VOTING POWER

                                0
                      --------- ------------------------------------------------
NUMBER OF                8      SHARED VOTING POWER
SHARES
BENEFICIALLY                    920,000
OWNED BY              --------- ------------------------------------------------
EACH                     9      SOLE DISPOSITIVE POWER
REPORTING
PERSON WITH                     0
                      --------- ------------------------------------------------
                         10     SHARED DISPOSITIVE POWER

                                920,000
----------- --------------------------------------------------------------------
    11      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON

            920,000
----------- --------------------------------------------------------------------
    12      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
            SHARES*                                                          [ ]

----------- --------------------------------------------------------------------
    13      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

            4.4%
----------- --------------------------------------------------------------------
    14      TYPE OF REPORTING PERSON*

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




     This Amendment No. 1 ("Amendment No. 1") amends the Schedule 13D filed on
January 14, 2005 and is being filed on behalf of Third Point LLC, a Delaware
limited liability company (the "Management Company"), and Daniel S. Loeb, an
individual ("Mr. Loeb" and, together with the Management Company, the "Reporting
Persons"). This Amendment No. 1 relates to the common stock, no par value, of
Infinity Property and Casualty Corporation, an Ohio corporation (the "Company").
Unless the context otherwise requires, references herein to the "Common Stock"
are to such common stock of the Company. The Management Company is the
investment manager or adviser to a variety of hedge funds and managed accounts
(such funds and accounts, collectively, the "Funds"). The Funds directly own the
Common Stock to which this Amendment No. 1 relates, and the Reporting Persons
may be deemed to have beneficial ownership over such Common Stock by virtue of
the authority granted to them by the Funds to vote and to dispose of the
securities held by the Funds, including the Common Stock.

Item 3. Source and Amount of Funds or Other Consideration.

     Item 3 of the initial Schedule 13D is hereby amended by deleting the
entirety of the text thereof and replacing it with the following:


     As of the filing of the initial Schedule 13D on January 14, 2005, the Funds
had expended an aggregate of $28,009,203.01 of their own investment capital to
acquire 1,150,000 shares of Common Stock. Since filing the initial Schedule 13D,
the Funds have expended an aggregate amount of approximately $2,772,673 to
acquire 88,200 shares of Common Stock, and have sold 318,200 shares of Common
Stock for proceeds in an aggregate amount of approximately $10,148,113. Such
shares were acquired in open market purchases.

     The Funds effect purchases of securities primarily through margin accounts
maintained for them with Bear, Stearns Securities Corp. and Goldman, Sachs & Co.
(the "Primary Brokers") which may extend margin credit to the Funds as and when
required to open or carry positions in the margin accounts, subject to
applicable Federal margin regulations, stock exchange


                                       4




rules and the firm's credit policies. In such instances, the positions held in
the margin accounts are pledged as collateral security for the repayment of
debit balances in the accounts.

Item 5. Interest in Securities of the Issuer.

     Item 5 of the initial Schedule 13D is hereby amended by deleting the
entirety of the text thereof and replacing it with the following:

     (a) As of the date of this Amendment No. 1, the Management Company
beneficially owns 920,000 shares of Common Stock. The Management Company shares
voting and dispositive power over such holdings with Mr. Loeb and with the
Funds. As of May 6, 2005, the Shares represented 4.4% of the total 20,685,748
shares of Common Stock outstanding at April 1, 2005 as reported in the Company's
definitive proxy statement on Schedule 14A filed April 12, 2005. None of the
individual Funds owns a number of shares of Common Stock equal to or greater
than 5% of such total Common Stock outstanding.


     (b) The Management Company and Mr. Loeb share voting and dispositive power
over the 920,000 shares of Common Stock held directly by the Funds.

     (c) Schedule A hereto sets forth certain information with respect to
transactions by the Funds, at the direction of the Reporting Persons, in the
Common Stock during the past sixty days.

     All of the transactions set forth on Schedule A, except as may be otherwise
noted therein, were effected in open market purchases on NASDAQ through the
Primary Brokers.

     Except as set forth above, during the last sixty days there were no
transactions in the Common Stock effected by the Reporting Persons, nor, to the
best of their knowledge, any of their directors, executive officers, general
partners or members.

     (d) Other than the Funds which directly hold the Shares, and except as set
forth in this Item 5, no person is known to have the right to receive or the
power to direct the receipt of dividends from, or the proceeds from the sale of,
the Shares.

     (e) The Reporting Persons ceased to beneficially own more than 5% of the
Common Stock on May 3, 2005.


                                       5




Item 7. Material to be Filed as Exhibits.

     1. Joint Filing Agreement, dated as of January 14, 2005, by and between the
Reporting Persons, incorporated herein by reference to Exhibit 1 of the initial
Schedule 13D filed on January 14, 2005.


                                       6




                                   Schedule A
                                   ----------

                   (Transactions by the Funds in Common Stock
                           during the past sixty days)


    Date            Transaction              Shares             Price Per Share

-----------------------------------------------------------------------------
  04/04/05             Buy                  63,100                 31.2000
-----------------------------------------------------------------------------
  04/04/05             Sell                (63,100)                31.2000
-----------------------------------------------------------------------------
  04/15/05             Sell                (100,000)               31.1515
-----------------------------------------------------------------------------
  05/03/05             Sell                (50,000)                32.8228
-----------------------------------------------------------------------------
  05/04/05             Sell                (50,000)                32.8111
-----------------------------------------------------------------------------
  05/04/05             Sell                (10,000)                32.7119
-----------------------------------------------------------------------------
  05/05/05             Sell                (20,000)                32.5738
-----------------------------------------------------------------------------




                                   SIGNATURES

     After reasonable inquiry and to the best of our knowledge and belief, the
undersigned certify that the information set forth in this statement is true,
complete and correct.


Dated: May 6, 2005


                                        THIRD POINT LLC

                                        By: /s/ Daniel S. Loeb
                                            ------------------------------
                                            Name:  Daniel S. Loeb
                                            Title: Managing Member


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














                        [SIGNATURE PAGE TO SCHEDULE 13D/A
                                 WITH RESPECT TO
                   INFINITY PROPERTY AND CASUALTY CORPORATION]