Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Corrigan Fredric W
   2. Issuer Name and Ticker or Trading Symbol
MOSAIC CO [MOS] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Executive Officer
(Last)
(First)
(Middle)
3033 CAMPUS DRIVE, SUITE E490		 3. Date of Earliest Transaction (Month/Day/Year)
10/06/2006
(Street)

PLYMOUTH, MN 55441		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock               15,000 D  
Common Stock               250 I by spouse

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Restricted Stock Units $ 0 (4)             10/29/2008   (1) Common Stock 86,437   86,437 D  
Stock Option (Right to Buy) $ 15.04             10/29/2007 10/29/2014 Common Stock 280,700   280,700 D  
Restricted Stock Units $ 0 (4)             08/01/2008   (1) Common Stock 92,764   92,764 D  
Stock Option (Right to Buy) $ 17.29             08/01/2006(2) 08/01/2015 Common Stock 278,293   278,293 D  
Restricted Stock Units $ 0 (4)             08/04/2009   (1) Common Stock 92,008   92,008 D  
Stock Option (Right to Buy) $ 15.45             08/04/2007(3) 08/04/2016 Common Stock 276,025   276,025 D  
Restricted Stock Unit $ 0 (4) 10/06/2006   A   19,646   10/06/2009   (1) Common Stock 19,646 $ 0 19,646 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Corrigan Fredric W
3033 CAMPUS DRIVE
SUITE E490
PLYMOUTH, MN 55441		   X     Chief Executive Officer  

Signatures

 s/Richard L. Mack, Attorney in fact for Fredric W. Corrigan   10/10/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Not applicable.
(2) Vests 33.33% on 8/1/2006, 8/1/2007 and 8/1/2008.
(3) Vests 33.33% on 8/4/2007, 8/4/2008 and 8/4/2009.
(4) one-for-one

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