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 *
MacAndrews & Forbes Holdings Inc.
   2. Issuer Name and Ticker or Trading Symbol
SIGA TECHNOLOGIES INC [SIGA] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
35 EAST 62ND STREET		 3. Date of Earliest Transaction (Month/Day/Year)
09/17/2009
(Street)

NEW YORK, NY 10065		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ 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, par value $.0001 per share 09/17/2009   X   326,797 A $ 3.06 (1) 5,962,032 I Owned through wholly-owned corporation
Common Stock, par value $.0001 per share               2,472,222 I Owned through partially-owned corporation

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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
Equity Line (2) (3) 09/17/2009   X     0 (2) (3)   (2)(3) 06/19/2010 Common Stock and Warrants (2) (3) $ 0 (2) (3) 1 I Owned through wholly-owned corporation
Warrant (Right to Buy) $ 3.519 09/17/2009   X   130,719   09/17/2009 09/17/2013 Common Stock 130,719 $ 0 (4) 130,719 I Owned through wholly-owned corporation

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MacAndrews & Forbes Holdings Inc.
35 EAST 62ND STREET
NEW YORK, NY 10065		     X    
PERELMAN RONALD O
35 EAST 62ND STREET
NEW YORK, NY 10065		     X    
MacAndrews & Forbes LLC
35 EAST 62ND STREET
NEW YORK, NY 10065		     X    

Signatures

 /s/ Barry F. Schwartz, Executive Vice Chairman   09/21/2009
**Signature of Reporting Person Date
 /s/ Barry F. Schwartz for Ronald O. Perelman pursuant to a Power of Attorney filed with the Securities and Exchange Commission   09/21/2009
**Signature of Reporting Person Date
 /s/ Barry F. Schwartz, Executive Vice Chairman   09/21/2009
**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) The shares were acquired by MacAndrews & Forbes LLC ("MacAndrews & Forbes"), a joint filer hereunder, pursuant to an exercise of the equity line agreement between SIGA Technologies, Inc. (the "Company") and MacAndrews & Forbes (the "Equity Line").
(2) The Equity Line provides that through June 19, 2010, (i) MacAndrews & Forbes commits to invest, at the Company's option, up to an aggregate of $8,000,000 in up to six tranches (such commitment, the "Investment Commitment") and (ii) MacAndrews & Forbes may, at MacAndrews & Forbes' option, elect to invest up to $8,000,000 in the Company in up to six tranches on the terms of the Investment Commitment (such option, the "Investment Option"); provided that in no event could the aggregate amount of the investments pursuant to the Investment Commitment and the Investment Option exceed $8,000,000. After giving effect to the present exercise, $5,500,000 of the Investment Commitment / Investment Option remains outstanding.
(3) Upon either of the Company's election to effect an investment pursuant to the Investment Commitment or MacAndrews & Forbes' election to effect an investment pursuant to the Investment Option (each, an "Investment") the Company shall issue to MacAndrews & Forbes: (i) such number of shares of Common Stock, with a value equal to the Investment, at a per share valuation ("Per Share Price") equal to the lesser of (A) $3.06 and (B) the average of the volume-weighted average price per share for the 5 trading days immediately preceding each funding date and (ii) warrants (the "Consideration Warrants"), for no additional consideration, to purchase a number of shares of Common Stock of the Company equal to 40% of the shares issued on such funding date, at an exercise price per share equal to 115% of the Per Share Price on such funding date, payable in cash or by cashless exercise, exercisable for a period of four years commencing on the date of issuance of such Consideration Warrants.
(4) The warrants were issued as Consideration Warrants in connection with the exercise of the Equity Line.
 
Remarks:
Ronald O. Perelman, a joint filer hereunder, beneficially owns 100% of the common stock of MacAndrews & Forbes Holdings Inc., which beneficially owns 100% of the equity interests of MacAndrews & Forbes LLC.  MacAndrews & Forbes LLC beneficially owns the securities described above as owned by wholly-owned corporation.

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