EXHIBIT 4(l)
                                                                   ------------

                          REGISTRATION RIGHTS AGREEMENT

            REGISTRATION RIGHTS AGREEMENT, dated as of August 13, 2003,
between SIGA Technologies, Inc., a Delaware corporation (the "Company"), and
MacAndrews & Forbes Holdings Inc., a Delaware corporation (the "Stockholder").

            In consideration of the mutual covenants and agreements herein
contained, the parties to this Agreement hereby agree as follows:

            1.   Definitions. As used in this Agreement, the following terms
shall have the following meanings:

            "Affiliate" means, with respect to any specified Person, (i) any
other Person 50% or more of whose outstanding voting securities are directly
or indirectly owned, controlled or held with the power to vote by such
specified Person or (ii) any other Person directly or indirectly controlling,
controlled by or under direct or indirect common control with such specified
Person.  For purposes of this definition, the term "control" means the
possession, directly or indirectly, of the power to direct or cause the
direction of the management or policies of a Person by virtue of ownership of
voting securities, by contract or otherwise.

            "Agreement" means this Registration Rights Agreement, including
all amendments, modifications and supplements and any exhibits or schedules
to any of the foregoing, and shall refer to this Registration Rights
Agreement as the same may be in effect at the time such reference becomes
operative.

            "Closing" has the meaning assigned to it in the Purchase
Agreement.

            "Common Stock" means common stock, par value $0.0001 per share,
of the Company.

            "Company" has the meaning assigned to it in the introductory
paragraph to this Agreement.

            "Demand Registration" has the meaning assigned to it in Section
2(a) hereof.





            "Demand Registration Statement" has the meaning assigned to it in
Section 2(a) hereof.

            "Exchange Act" means the Securities Exchange Act of 1934, as
amended, and the rules and regulations promulgated thereunder.

            "Holder" means the Stockholder and any other Person that holds
Registrable Securities, including their respective transferees, successors
and assigns who acquire Registrable Securities, directly or indirectly, from
the Stockholder or such other Person, respectively.  For purposes of this
Agreement, the Company may deem and treat the registered holder of a
Registrable Security as the Holder and absolute owner thereof, and the
Company shall not be affected by any notice to the contrary.

            "Holder Shares" has the meaning assigned to it in Section 5
hereof.

            "Initially Proposed Shares" has the meaning assigned to it in
Section 5 hereof.

            "Inspectors" has the meaning assigned to it in Section 6(a)(xiii)
hereof.

            "Majority Holder" has the meaning assigned to it in Section 2(a)
hereof.

            "Participating Holder" has the meaning assigned to it in Section
6(a)(i) hereof.

            "Permitted Transferee" means (i) any Affiliate of the Holder,
including, without limitation, directors, executives and officers of the
Holder, (ii) any member of the family of any Affiliate of the Holder,
including any such Person's spouse and descendants and any trust,
partnership, corporation, limited liability company or other entity for the
benefit of such spouse and/or descendants to whom or which any of the
Registrable Securities have been transferred by any such Person for estate or
tax planning purposes, (iii) any charity or foundation to which the
Securities have been transferred by the Holder or any Person or entity
described in clause (i) or (ii) above for estate or tax planning or
charitable purposes, or (iv) the beneficiary of any bona fide pledge by the
Holder of any of the Registrable Securities.


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            "Person" means any individual, sole proprietorship, partnership,
limited liability company, joint venture, trust, incorporated organization,
association, corporation, institution, governmental agency or authority or
other entity.

            "Purchase Agreement" means the Securities Purchase Agreement by
and between the Company and the Stockholder, dated as of the date hereof.

            "Registrable Securities" means (a) any shares of Common Stock
owned by a Holder, (b) the Warrant Shares, and (c) any securities issued or
issuable in respect of Common Stock or other capital stock referred to in
clauses (a) and (b) above by way of conversion, exercise or exchange or any
stock dividend or stock split or in connection with a combination of shares,
recapitalization, reclassification, merger or consolidation, and any other
securities issued pursuant to any other pro rata distribution with respect to
such Common Stock or other capital stock.  For purposes of this Agreement, a
Registrable Security ceases to be a Registrable Security when (x) it has been
effectively registered under the Securities Act and sold or distributed to
the public in accordance with an effective registration statement covering it
(and has not been reacquired in the manner described in clause (c) above), or
(y) it is sold or distributed to the public pursuant to Rule 144 (or any
successor or similar provision) under the Securities Act.

            "Registration Expenses" has the meaning assigned to it in Section
6(e) hereof.

            "S-3 Registration" has the meaning assigned to it in Section 4
hereof.

            "SEC" means the U.S. Securities and Exchange Commission.

            "Securities Act" means the Securities Act of 1933, as amended,
and the rules and regulations promulgated thereunder.

            "Shelf Registration Statement" has the meaning assigned to it in
Section 3(a) hereof.

            "Shelf Registration Period" means, with respect to each Shelf
Registration Statement, the earliest to occur of (i) the sale of all the
Registrable Securities registered on such Registration Statement, or (ii)
four years from the date of the later of (x) the date of the final issuance
of Warrant Shares upon exercise of the Warrants registered on such Shelf
Registration Statement or (y) the date of the effectiveness of such Shelf
Registration Statement; provided, however, the Shelf Registration Period
shall be extended by the aggregate number of days a Shelf Registration
Statement is postponed pursuant to Section 3(e) hereof.


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            "Stockholder" has the meaning assigned to it in the introductory
paragraph to this Agreement.

            "Subject Shares" has the meaning assigned to it in Section 6(a)
hereof.

            "Warrant Shares" means the shares of Common Stock issued or
issuable upon exercise of the Warrants.

            "Warrants" means the warrants to acquire Common Stock issued
pursuant to the Purchase Agreement.

            2.   Demand Registration.
                 --------------------

            (a)  If registration on a Shelf Registration Statement pursuant
to Section 3 hereof is not available to a Holder or Holders at any time, then
upon the request in writing of any Holder or Holders who together hold a
majority of the then outstanding Registrable Securities (the "Majority Holder")
to register under the Securities Act all or a part of the Registrable Securities
held by such Majority Holder (a "Demand Registration"), the Company shall use
all reasonable efforts to cause to be filed as soon as reasonably practicable
(but in no event later than the 60th day after such Majority Holder's request is
made) a registration statement providing for the sale of all such Registrable
Securities to be registered by such Majority Holder, and shall use all
reasonable efforts to cause such registration statement to be declared effective
within 60 days of such filing, including, but not limited to, a sale of such
Registrable Securities in connection with the issuance of any securities
convertible into or exchangeable or exercisable for Registrable Securities or
the sale of Registrable Securities upon conversion, exercise or exchange
thereof; provided, that, the anticipated offering price of each Demand
Registration shall be at least $5,000,000. The Company agrees to use its
reasonable efforts to keep any such registration statement continuously
effective and usable for resale of Registrable Securities for a period of not
less than 180 days, or such shorter period as is necessary to complete the
distribution of the securities covered by such registration statement. Each
registration statement filed pursuant to this Section 2(a) is hereinafter
referred to as a "Demand Registration Statement." The Company may, if permitted
by law, effect any registration pursuant to this Section 2(a) by the filing of a
registration statement on Form S-3. However, if such registration involves an
underwritten public offering and the managing underwriter(s) at any time shall
notify the Company in writing that, in the sole judgment of such managing
underwriter(s), inclusion of some or all of the information required in a more
detailed form specified in such notice is of material importance to the success
of the public offering of such


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Registrable Securities, the Company shall use all reasonable efforts to
supplement or amend such registration statement to include such information.

            (b)  Subject to the provisions of Section 2(a), the Majority Holder
shall be entitled to request no more than two Demand Registrations. A
registration shall not count as one of the permitted Demand Registrations unless
(i) the registration statement filed in connection therewith has become
effective, (ii) the Majority Holder requesting such registration is able to
register and sell at least 50% of the Registrable Securities requested by such
Majority Holder to be included in such registration or (iii) in the case of a
Demand Registration that would be the last permitted Demand Registration
requested hereunder, the Majority Holder requesting such registration is able to
register and sell all of the Registrable Securities requested to be included by
such Majority Holder in such registration. Notwithstanding the foregoing, a
registration shall count as one of the permitted Demand Registrations if the
registration statement in connection therewith is filed and subsequently
withdrawn, at the request of the Majority Holder, unless all Registration
Expenses with respect to such withdrawn registration statement are paid by such
Majority Holder.

            (c)  The Company shall not effect any public or private sale,
distribution or purchase of any of its securities which are the same as or
similar to the Registrable Securities, including a sale pursuant to Regulation D
under the Securities Act, during the 15-day period prior to, and during the
30-day period beginning on, the closing date of each underwritten offering under
any Demand Registration Statement.

            (d)  The Company may postpone for a reasonable period of time, not
to exceed 45 days, the filing or the effectiveness of any Demand Registration
Statement if (i) the board of directors of the Company in good faith determines
that (A) such registration would have a material adverse effect on any plan or
proposal by the Company with respect to any financing, acquisition,
recapitalization, reorganization or other material transaction, or (B) the
Company is in possession of material non-public information that, if publicly
disclosed, would result in a material disruption of a major corporate
development or transaction then pending or in progress or in other material
adverse consequences to the Company, and (ii) the Company so notifies the
Majority Holder within five days after the Majority Holder requests such
registration. The Company's right to defer the filing of a registration
statement pursuant to the provisions of the preceding sentence may not be
exercised more than twice during any 12-month period.


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            (e)  If at any time the Majority Holder notifies the Company in
writing of the Majority Holder's desire that the Registrable Securities to be
covered by a Demand Registration Statement be sold in an underwritten offering,
such Majority Holder shall have the right to select any nationally recognized
investment banking firm(s) to administer the offering, subject to the approval
of the Company, which approval shall not be unreasonably withheld, and the
Company shall enter into underwriting agreements with the underwriter(s) of such
offering, which agreements shall contain such representations and warranties by
the Company, and such other terms, conditions and indemnities as are at the time
customarily contained in underwriting agreements for similar offerings and the
Company shall take or cause to be taken all such other actions, in addition to
the registration procedures set forth in Section 6 hereof, as are reasonably
requested by the managing underwriter(s) in order to expedite or facilitate the
registration and disposition of the Registrable Securities, including, without
limitation, causing management to participate in "road show" presentations.

            3.   Shelf Registration.
                 -------------------

            (a)  No later than 45 days after each Closing under the Purchase
Agreement, the Company shall file with the SEC a "shelf" Registration Statement
(each, a "Shelf Registration Statement") on Form S-3 (or, if Form S-3 is not
then available, on such form of Registration Statement as is then available to
effect a registration of the Registrable Securities), covering the resale of
such number of shares of Registrable Securities as shall equal the sum of the
number of (x) shares of Common Stock issued at such Closing, (y) the shares of
Common Stock issued or issuable upon exercise of the Warrants issued at such
Closing and (z) any shares of Common Stock issued or issuable with respect to
the shares of Common Stock issued or issuable and referred to in clause (x) or
(y) of this sentence by way of exercise, exchange or any stock dividend or stock
split or in connection with a combination of shares, recapitalization,
reclassification, merger or consolidation, and any other securities issued
pursuant to any other pro rata distribution with respect to such Common Stock or
other capital stock.

            (b)  The Shelf Registration Statements, to the extent allowable
under the Securities Act (including Rule 416 under the Securities Act), shall
state that such Shelf Registration Statement also covers such indeterminate
number of additional shares of Common Stock as may become issuable upon the
exercise of the Warrants to prevent dilution resulting from certain issuances of
Common Stock, adjustments upon stock dividends, stock subdivisions, spin offs,
reclassifications, reorganizations, consolidations, mergers, stock splits, or
otherwise.


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            (c)  The Company shall use its reasonable best efforts to cause each
Shelf Registration Statement to be effective no later than 90 days after the
date it is first filed with the SEC.

            (d)  The Company shall keep each Shelf Registration Statement
effective pursuant to Rule 415 under the Securities Act at all times until the
expiration of the applicable Shelf Registration Period (except during the period
of any postponement pursuant to paragraph (e) of this Section 3). In the event
the number of shares available under a Shelf Registration Statement filed
pursuant to this Agreement is insufficient to cover all of the Registrable
Securities issued or issuable upon the exercise of the Warrants to prevent
dilution resulting from certain issuances of Common Stock, adjustments upon
stock dividends, stock subdivisions, spin offs, reclassifications,
reorganizations, consolidations, mergers, stock splits, or otherwise, the
Company shall amend such Shelf Registration Statement, or file a new Shelf
Registration Statement (on the short form available therefor, if applicable), or
both, so as to cover all of the Registrable Securities, in each case, as soon as
practicable, but in any event within 10 business days after the necessity
therefor arises. The Company shall use its best efforts to cause such amendment
and/or new Shelf Registration Statement to become effective as soon as
practicable following the filing thereof.

            (e)  The Company may postpone for a reasonable period of time, not
to exceed 45 days, the filing or the effectiveness of any Shelf Registration
Statement if (i) the board of directors of the Company in good faith determines
that (A) such registration would have a material adverse effect on any plan or
proposal by the Company with respect to any financing, acquisition,
recapitalization, reorganization or other material transaction, or (B) the
Company is in possession of material non-public information that, if publicly
disclosed, would result in a material disruption of a major corporate
development or transaction then pending or in progress or in other material
adverse consequences to the Company, and (ii) the Company so notifies the
Majority Holder within five days after the Majority Holder request such
registration. The Company's right to defer the filing of a registration
statement pursuant to the provisions of the preceding sentence may not be
exercised more than twice during any 12-month period.

            4.   S-3 Registrations. If registration on a Shelf Registration
Statement pursuant to Section 3 hereof is not available to a Holder or Holders
at any time, then if such Holder or Holders request in writing that the Company
file a Registration Statement on Form S-3 or any successor thereto for a public
offering of all or any portion of the Registrable Securities held by such
Holders, the Company shall use its reasonable best efforts to register under the
Securities Act on Form S-3


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or any successor thereto (an "S-3 Registration"), for public sale in accordance
with the method of disposition specified in such notice, the number of shares of
Registrable Securities specified in such notice; provided, however, that (i) no
more than two such S-3 Registrations shall be required in any 12-month period
and (ii) the Company shall have no obligation to register such Registrable
Securities pursuant to this Section 4 if the anticipated aggregate offering
price in such S-3 Registration shall not be at least $500,000. There is no
limitation on the number of registrations that the Company is obligated to
effect pursuant to this Section 4.

            5.   Incidental Registration. Subject to the terms and conditions
set forth in this Section 5 and unless otherwise registered pursuant to any
other section hereof or otherwise, if the Company proposes at any time to
register any equity securities (the "Initially Proposed Shares") under the
Securities Act, whether or not for its own account, the Company will promptly
give written notice to the Holders of its intention to effect such registration
(such notice to specify, among other things, the proposed offering price (if
applicable), the kind and number of securities proposed to be registered and the
distribution arrangements, including identification of the underwriter(s), if
any), and the Holders shall be entitled to include in such registration such
number of Registrable Securities (the "Holder Shares") to be sold for the
account of the Holders (on the same terms and conditions as the Initially
Proposed Shares) as shall be specified in a request in writing delivered to the
Company within 15 days after the receipt of the Company's notice.

            The Company's obligations to include Holder Shares in a
registration statement pursuant to this Section 5 is subject to each of the
following limitations, conditions and qualifications:

                 (i)  If, at any time after the Company gives written notice to
      the Holders of its intention to effect a registration of any of its equity
      securities (whether or not for its own account) and prior to the effective
      date of any registration statement filed in connection with such
      registration, either the Company (in the case of the Company intending to
      register securities for its own account) or holders of Company securities
      (in the case of the Company intending to register securities on behalf of
      holders of securities other than Registrable Securities) shall determine
      for any reason not to register any securities which were theretofore the
      subject of such registration, the Company shall give written notice of
      such determination to the Holders and thereupon it shall be relieved of
      its obligation to use any efforts to register any Holder Shares in
      connection with such aborted registration (but not from its obligation to
      pay the Registration Expenses in connection therewith).


                                       8



                 (ii) If the managing underwriter(s) (in the case of an
      underwritten offering) of such offering shall notify in writing the
      Company and each Holder who shall have requested the inclusion of
      Registrable Securities in such underwritten offering that, in the good
      faith judgment of such managing underwriter(s), the distribution of all or
      a specified portion of the Holder Shares would materially interfere with
      the registration and sale, in accordance with the intended method thereof,
      of the Initially Proposed Shares, then the number of Holder Shares to be
      included in such registration statement shall be reduced to such number,
      if any, that, in the good faith judgment of such managing underwriter(s),
      can be included without such interference; provided, however, that, if

                 (1)  the Initially Proposed Shares were being registered by the
                      Company for its own account, then the number of securities
                      to be included in such registration shall be allocated (x)
                      first, to the Company, and (y) second, pro rata among all
                      holders of Company securities (including the Holders) on
                      the basis of the number of shares requested to be included
                      in such registration statement by such holders; and

                 (2)  the Initially Proposed Shares were being registered by the
                      Company for the account of holders of Company securities
                      (other than the Holders), then the number of securities to
                      be included in such registration shall be allocated (x)
                      first, pro rata among the holders of Company securities
                      (other than Holders) requesting such registration based
                      upon the number of securities each such holder requested
                      be included in such registration, and (y) second, pro rata
                      among all holders of Company securities not included in
                      the foregoing clause (x) (including Holders) and the
                      Company on the basis of the number of shares requested to
                      be included in such registration statement by such holders
                      and the Company.

                 (iii) If, as a result of the cutback provisions contained in
      Section 5(ii) hereof, the Holders are not entitled to include all of the
      Holder Shares in such registration, such Holders may elect to withdraw
      their request to include Holder Shares in such registration.


                                       9



                 (iv) If the Company shall so deliver such a request in writing
      to the Holders, each Holder shall not effect any public or private sale or
      distribution of any Registrable Securities (other than the Holder Shares)
      during the 15-day period prior to, and during the 45-day period beginning
      on, the closing date of any underwritten public offering of shares of
      Common Stock made for the Company's own account.

            6.   Registration Procedures.
                 ------------------------

            (a)  Whenever the Company is required to effect the registration of
any Registrable Securities under the Securities Act pursuant to the terms and
conditions of Section 2, 3, 4 or 5 hereof (such Registrable Securities being
hereinafter referred to as "Subject Shares"), the Company will use all
reasonable efforts to effect the registration and sale of the Subject Shares in
accordance with the intended method of disposition thereof. Without limiting the
generality of the foregoing, the Company will as soon as practicable:

                 (i)  furnish to each Holder of Subject Shares (a "Participating
      Holder") and to each managing underwriter, if any, a reasonable time in
      advance of their filing with the SEC, any registration statement,
      amendment (or post-effective amendment) or supplement thereto, and any
      prospectus used in connection therewith, and each Participating Holder
      shall have, within a reasonable period of time, the opportunity to object
      to any information pertaining to such Participating Holder and its plan of
      distribution that is contained therein and the Company will make the
      corrections reasonably requested by such Participating Holder with respect
      to such information prior to filing any such registration statement or any
      amendment or supplement thereto; and furnish a copy of any and all
      transmittal letters or other correspondence with the SEC or any other
      governmental agency or self-regulatory body or other body having
      jurisdiction (including any domestic or foreign securities exchange)
      relating to such offering of Registrable Securities;

                 (ii) prepare and file with the SEC registration statements with
      respect to the Subject Shares in form and substance reasonably
      satisfactory to the Participating Holders, and use all reasonable efforts
      to cause such registration statements to become effective as soon as
      possible;

                 (iii) prepare and file with the SEC such amendments (including
      post-effective amendments) and supplements to each registration statement
      and the prospectus used in connection therewith as may be




                                       10


      necessary to keep each such registration statement effective for the
      applicable period (or, in the case of a Shelf Registration Statement, the
      applicable Shelf Registration Period (except during the period of any
      postponement pursuant to Section 3(e) hereof)) and to comply with the
      provisions of the Securities Act with respect to the disposition of all
      Subject Shares and other securities covered by such registration
      statements (until such time, in the case of a Shelf Registration
      Statement, as all of such Registrable Securities have been disposed of in
      accordance with the intended methods of disposition by the seller or
      sellers thereof as set forth in such Shelf Registration Statement);

                 (iv)  furnish each Participating Holder and each managing
      underwriter, if any, without charge, such number of copies of such
      registration statement, each amendment and supplement thereto (in each
      case including all exhibits thereto and documents incorporated by
      reference therein) and the prospectus included in such registration
      statement (including each preliminary prospectus and prospectus
      supplement) and any other prospectus filed under Rule 424 promulgated
      under the Securities Act relating to the Registrable Securities and such
      other documents as such Participating Holder or such underwriter may
      reasonably request;

                 (v)  after the filing of each registration statement, promptly
      notify each Participating Holder and each managing underwriter, if any, of
      any stop order issued or, to the knowledge of the Company, threatened to
      be issued by the SEC;

                 (vi) use all reasonable efforts to register or qualify the
      Subject Shares covered by such registration statement under the securities
      or blue sky laws of such jurisdictions (including any foreign country or
      any political subdivision thereof) as the managing underwriter(s), if any,
      shall reasonably recommend, and do any and all other acts and things which
      may be reasonably necessary or advisable to enable the Participating
      Holders to consummate the disposition in such jurisdictions of the Subject
      Shares covered by such registration statement, except that the Company
      shall not for any such purpose be required to (A) qualify generally to do
      business as a foreign corporation in any jurisdiction wherein it is not so
      qualified, (B) subject itself to taxation in any jurisdiction wherein it
      is not so subject, or (C) consent to general service of process in any
      such jurisdiction or otherwise take any action that would subject it to
      the general jurisdiction of the courts of any jurisdiction in which it is
      not so subject;


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                 (vii) promptly inform each Participating Holder and the
      managing underwriter(s), if any, (x) in the case of any offering of the
      Registrable Securities in respect of which a registration statement is
      filed under the Securities Act, of the date on which a registration
      statement or any post-effective amendment thereto has been filed and when
      the same has become effective and, if applicable, of the date of filing a
      Rule 430A prospectus, (y) of any written comments from the SEC with
      respect to any filing referred to in clause (x) and of any request by the
      SEC, any securities exchange, government agency, self-regulatory body or
      other body having jurisdiction for any amendment of or supplement to any
      registration statement or preliminary prospectus or prospectus included
      therein or any offering memorandum or other offering document relating to
      such offering or (z) of the receipt by the Company of any notification
      with respect to the suspension of the qualification of any Registrable
      Securities for sale under the applicable securities or blue sky laws of
      any jurisdiction;

                 (viii) otherwise use its reasonable efforts to comply with all
      applicable rules and regulations of the SEC;

                 (ix) provide a transfer agent and registrar for all Registrable
      Securities covered by such registration statement not later than the
      effective date of such registration statement;

                 (x) furnish, at the Company's expense, unlegended certificates
      representing ownership of the securities being sold in such denominations
      as shall be requested and instruct the transfer agent to release any stop
      transfer orders with respect to the Subject Shares being sold;

                 (xi) notify each Participating Holder at any time when a
      prospectus relating to the Subject Shares is required to be delivered
      under the Securities Act of the happening of any event as a result of
      which the prospectus included in such registration statement contains any
      untrue statement of a material fact or omits to state a material fact
      necessary to make the statements therein (in the case of the prospectus or
      any preliminary prospectus, in light of the circumstances under which they
      were made) not misleading, and the Company will promptly thereafter
      prepare and file with the SEC and furnish a supplement or amendment to
      such prospectus so that, as thereafter delivered to the purchasers of
      Subject Shares, such prospectus will not contain any untrue statement of a
      material fact or omit to state a material fact required to be stated
      therein or necessary to make the statements


                                       12



      therein (in the case of the prospectus or any preliminary prospectus, in
      light of the circumstances under which they were made) not misleading;

                 (xii) enter into customary agreements (including, but not
      limited to, an underwriting agreement in customary form in the case of an
      underwritten offering) and make such representations and warranties to the
      sellers, underwriter(s), placement agents and other financial
      intermediaries as in form and substance and scope are customarily made by
      issuers to such parties and take such other actions as the Holders or such
      other parties, if any, reasonably require in order to expedite or
      facilitate the disposition of such Subject Shares. A Participating Holder
      may, at its option, require that any or all of the representations and
      warranties by, and the other agreements on the part of, the Company to and
      for the benefit of such other parties also be made to and for the benefit
      of any one or more Participating Holders, and that any or all of the
      conditions precedent to the obligations of such other parties under such
      agreement also be conditions precedent to the obligations of the
      Participating Holders;

                 (xiii) make available for inspection by the Participating
      Holders, any underwriter, agent or other financial intermediary
      participating in any disposition pursuant to such registration statement,
      and any one attorney, accountant or other similar professional advisor
      retained by any such Participating Holders or underwriter (collectively,
      the "Inspectors"), all pertinent financial and other records, pertinent
      corporate documents and properties of the Company, as shall be reasonably
      necessary to enable them to exercise their due diligence responsibility,
      and cause the Company's officers, directors and employees to supply all
      information reasonably requested by any such Inspector in connection with
      such registration statement;

                 (xiv) make available senior management personnel of the Company
      to participate in, and cause them to cooperate with any underwriter, agent
      or other financial intermediary in connection with, "road show" and other
      customary marketing activities, including "one-on-one" meetings with
      prospective purchasers of the Subject Shares;

                 (xv) obtain for delivery to the Company, any underwriter, agent
      or other financial intermediary or their agents, with copies to the
      Participating Holders, a "cold comfort" letter from the Company's
      independent public accountants in customary form and covering such matters
      of the type customarily covered by "cold comfort" letters as the
      Participating


                                       13



      Holders or the managing underwriter, agent or other financial intermediary
      reasonably request;

                 (xvi) obtain for delivery to the Participating Holders and any
      underwriter, agent or other financial intermediary or their agents an
      opinion or opinions from counsel for the Company in customary form and
      reasonably satisfactory to the Participating Holders, underwriters or
      agents and their counsel;

                 (xvii) make available to its security holders consolidated
      earnings statements, which need not be audited, satisfying the provisions
      of Section 11(a) of the Securities Act, no later than 90 days after the
      end of the 12-month period beginning with the first month of the Company's
      first quarter commencing after the effective date of such registration
      statement, which earnings statements shall cover said 12-month period;

                 (xviii) make every reasonable effort to prevent the issuance of
      any stop order suspending the effectiveness of any such registration
      statement or of any order preventing or suspending the effectiveness of
      such registration statement at the earliest possible moment;

                 (xix) cause the Subject Shares to be registered with or
      approved by such other governmental agencies or authorities (including
      foreign governmental agencies and authorities) as may be necessary to
      enable the sellers thereof or any underwriter, agent or other financial
      intermediary to consummate the disposition of such Subject Shares;

                 (xx) cooperate with the Holders and the managing
      underwriter(s), if any, or any other interested party (including any
      interested broker-dealer) in making any filings or submission required to
      be made, and the furnishing of all appropriate information in connection
      therewith, with the National Association of Securities Dealers, Inc.;

                 (xxi) cause its subsidiaries to take action necessary to effect
      the registration of the Subject Shares contemplated hereby, including
      filing any required financial information;

                 (xxii) effect the listing of the Subject Shares on The Nasdaq
      SmallCap Market or such other national securities exchange or
      over-the-counter market on which shares of the Common Stock shall then be
      listed or shall otherwise be requested by the Holders; and


                                       14



                 (xxiii) take all other steps reasonably necessary to effect the
      registration of the Subject Shares contemplated hereby.

            (b)  The Holders shall provide (in writing and signed by the Holders
and stated to be specifically for use in the related registration statement,
preliminary prospectus, prospectus or other document incident thereto) all such
information and materials and take all such action as may be required in order
to permit the Company to comply with all applicable requirements of the SEC and
any applicable state securities laws and to obtain any desired acceleration of
the effective date of any registration statement prepared and filed by the
Company pursuant to this Agreement.

            (c)  The Holders shall, if requested by the Company or the managing
underwriter(s), if any, in connection with any proposed registration and
distribution pursuant to this Agreement, (i) agree to sell the Subject Shares on
the basis provided in any underwriting arrangements entered into in connection
therewith and (ii) complete and execute all questionnaires, powers of attorney,
indemnities, underwriting agreements and other documents customary in similar
offerings; provided, however, that in no event shall a Participating Holder be
required to make any representations or warranties to or agreements with the
Company or the underwriter(s) other than representations, warranties or
agreements regarding such Participating Holder and its ownership of the
securities being registered on its behalf and its intended method of
distribution and any other representation required by law.

            (d)  Upon receipt of any notice from the Company that the Company
has become aware that the prospectus (including any preliminary prospectus)
included in any registration statement filed pursuant to Section 2, 3, 4 or 5
hereof, as then in effect, contains any untrue statement of a material fact or
omits to state any material fact required to be stated therein or necessary to
make the statements therein not misleading, the Holders shall forthwith
discontinue disposition of Subject Shares pursuant to the registration statement
covering the same until the Holders' receipt of copies of a supplemented or
amended prospectus and, if so directed by the Company, deliver to the Company
(at the Company's expense) all copies other than permanent file copies then in
the Holder's possession, of the prospectus covering the Subject Shares that was
in effect prior to such amendment or supplement.

            (e)  The Company shall pay all Registration Expenses. For purposes
of this Agreement, "Registration Expenses" shall mean all expenses incident to
the Company's performance of or compliance with its obligations under


                                       15



this Agreement to effect the registration of Registrable Securities pursuant to
Section 2, 3, 4 or 5 hereof, and the disposition of such securities, including,
without limitation, all registration, filing, qualification and other fees and
expenses of complying with securities or blue sky laws, transfer agents and
registrars' fees, all word processing, duplicating and printing expenses, the
reasonable fees and disbursements of one counsel retained by the Participating
Holders and the fees and disbursements of counsel for the Company and of its
independent public accountants, including the expenses of any special audits or
"cold comfort" letters required by or incident to such performance and
compliance, but excluding underwriting discounts and commissions in respect of
Registrable Securities (which underwriting discounts and commissions shall be
paid by the Participating Holders).

            (f)  In connection with any sale of Subject Shares that are
registered pursuant to this Agreement, the Company and the Holders shall enter
into an agreement providing for indemnification of the Holders by the Company,
and indemnification of the Company by the Holders, on terms customary for such
agreements at that time.

            7.   Notices. All notices, requests, consents and other
communications required or permitted hereunder shall be in writing and shall be
hand delivered or mailed postage prepaid by registered or certified mail or
transmitted by facsimile transmission (with immediate telephonic confirmation
thereafter),

            If to the Company, to:

            SIGA Technologies, Inc.
            420 Lexington Avenue, Suite 601
            New York, New York 10120
            Attention:      Thomas N. Konatich
            Facsimile No.:  (212) 697-3130

            with a copy (which shall not constitute notice) to:

            Kramer, Levin, Naftalis & Frankel LLP
            919 Third Avenue
            New York, New York 10022
            Attention:        James A. Grayer, Esq.
            Facsimile No.:  (212) 715-8000

            If to the Stockholder, to:


                                       16



            MacAndrews & Forbes Holdings Inc.
            35 East 62nd Street
            New York, New York 10021
            Attention:  Barry F. Schwartz, Esq.
            Facsimile No.: (212) 572-5056

            with a copy (which shall not constitute notice) to:

            Skadden, Arps, Slate, Meagher & Flom LLP
            Four Times Square
            New York, New York 10036
            Attention: Franklin M. Gittes, Esq. and
                           Alan C. Myers, Esq.
            Facsimile: (212) 735-2000

            If to any other Holder,

            to such name at such address as such Holder shall have indicated
            in a written notice delivered to the other parties to this
            Agreement,

or at such other address as the Company or the Stockholder may specify by
written notice to the other, and each such notice, request, consent and other
communication shall for all purposes of the Agreement be treated as being
effective or having been given when delivered if delivered personally, upon
receipt of facsimile confirmation if transmitted by facsimile, or, if sent by
mail, at the earlier of its receipt or 72 hours after the same has been
deposited in a regularly maintained receptacle for the deposit of United
States mail, addressed and postage prepaid as aforesaid.

            8.  Waivers. No waiver by any party of any default with respect to
any provision, condition or requirement hereof shall be deemed to be a
continuing waiver in the future thereof or a waiver of any other provision,
condition or requirement hereof, nor shall any delay or omission of any party to
exercise any right hereunder in any manner impair the exercise of any such right
accruing to it thereafter.

            9.  Interpretation. When a reference is made in this Agreement to a
section, article, paragraph, clause, annex or exhibit, such reference shall be
to a reference to this Agreement unless otherwise clearly indicated to the
contrary. The descriptive article and section headings herein are intended for
convenience of reference only and are not intended to be a part of or to affect
the meaning or


                                       17



interpretation of this Agreement. Whenever the words "include," "includes" or
"including" are used in this Agreement they shall be deemed to be followed by
the words "without limitation." The words "hereof," "herein" and "herewith" and
words of similar import shall, unless otherwise stated, be construed to refer to
this Agreement as a whole and not to any particular provision of this Agreement.
The meaning assigned to each term used in this Agreement shall be equally
applicable to both the singular and the plural forms of such term, and words
denoting either gender shall include both genders. Where a word or phrase is
defined herein, each of its other grammatical forms shall have a corresponding
meaning.

            10.  Amendment. This Agreement may be amended, modified or
supplemented by the parties hereto at any time. This Agreement may not be
amended except by a written instrument executed by the parties hereto.

            11.  Successors and Assigns. This Agreement shall inure to the
benefit of and be binding upon the successors and assigns of each of the
parties. The Holder's rights under this Agreement may be assigned, in whole or
in part, to (a) any Permitted Transferee, and any Permitted Transferee shall be
deemed to be a Holder for all purposes hereunder or (b) any transferee of
Registrable Securities that has acquired (x) the greater of (A) 10% of the
Registrable Securities held by such transferor on the date of such transfer and
(B) 68,298 Registrable Securities (appropriately adjusted for any stock split,
combination, reorganization, recapitalization, reclassification, stock dividend,
stock distribution or similar event) or (y) if the transferor shall then hold
less than 68,298 Registrable Securities (appropriately adjusted for any stock
split, combination, reorganization, recapitalization, reclassification, stock
dividend, stock distribution or similar event), all of Registrable Securities
held by such transferor, and any such transferee shall be deemed to be a Holder
for all purposes hereunder; provided, that, no such assignment shall be
effective or confer any right on any such assignee unless, prior to such
assignment, the assignee agrees in writing, in form and substance reasonably
satisfactory to the Company, that such assignee will be bound by all provisions
binding on a Holder hereunder; provided, further, that any beneficiary of a
pledge described in clause (iv) of the definition of "Permitted Transferee"
above shall not be required to agree in writing to be bound by the terms hereof;
it being understood that subsequent Holders are intended third party
beneficiaries hereof.

            12.  Governing Law. The internal laws, and not the laws of conflicts
(other than Section 5-1401 of the General Obligations Law of the State of New
York), of New York shall govern the enforceability and validity of this
Agreement, the construction of its terms and the interpretation of the rights
and duties of the parties.


                                       18



            13.  Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original but all of which shall
be considered one and the same agreement.

            14.  Entire Agreement. This Agreement constitutes the entire
agreement, and supersedes all prior agreements and understandings (written and
oral) between the parties with respect to the subject matter hereof.

            15.  Available Information. If at any time the Company is required
to file reports in compliance with either Section 13 or Section 15(d) of the
Exchange Act, the Company will comply with all rules and regulations of the SEC
applicable in connection with the use of Rule 144 or Rule 144A promulgated under
the Securities Act and will, upon the request of any Holder, take such other
actions and furnish the Holder with information as the Holder may reasonably
request in order to avail itself of such rule or any other rule or regulation of
the SEC allowing the Holder to sell any Registrable Securities without
registration, and will, at its expense, forthwith upon the request of the
Holder, deliver to such party a certificate, signed by the Company's principal
financial officer, stating (a) the Company's name, address and telephone number
(including area code), (b) the Company's Internal Revenue Service identification
number, (c) the Company's SEC file number, (d) the number of shares of each
class of stock outstanding as shown by the most recent report or statement
published by the Company, and (e) whether the Company has filed the reports
required to be filed under the Exchange Act for a period of at least 90 days
prior to the date of such certificate and in addition has filed the most recent
annual report required to be filed thereunder or as to such matters as would
then be required to establish compliance with Rule 144 or any successor rule or
rules under the Securities Act. If at any time the Company is not required to
file reports in compliance with either Section 13 or Section 15(d) of the
Exchange Act, the Company at its expense will, forthwith upon the written
request of the Holder, make available adequate current public information with
respect to the Company within the meaning of paragraph (c)(2) of Rule 144.

            16.  Specific Performance. Irreparable damage would occur in the
event that any of the provisions of this Agreement were not performed in
accordance with their specific terms or were otherwise breached; accordingly,
the parties hereto shall be entitled to an injunction or injunctions to prevent
breaches of this Agreement and to enforce specifically the terms and provisions
hereof in any court of the United States or any state having jurisdiction, this
being in addition to any other remedy to which they are entitled at law or in
equity.


                                       19



            17.  Severability. If any term, provision, covenant or restriction
of this Agreement is held by a court of competent jurisdiction or other
authority to be invalid, void, unenforceable or against its regulatory policy,
the remainder of the terms, provisions, covenants and restrictions of this
Agreement shall remain in full force and effect and shall in no way be affected,
impaired or invalidated.

            18.  Submission to Jurisdiction. Any suit, action or proceeding
seeking to enforce any provision of, or based on any matter arising out of or in
connection with, this Agreement or the transactions contemplated hereby may be
brought in any federal or state court located in the County and State of New
York, and each of the parties hereby consents to the jurisdiction of such courts
(and of the appropriate appellate courts therefrom) in any such suit, action or
proceeding and irrevocably waives, to the fullest extent permitted by law, any
objection which it may now or hereafter have to the laying of the venue of any
such suit, action or proceeding in any such court or that any such suit, action
or proceeding which is brought in any such court has been brought in an
inconvenient forum. Process in any such suit, action or proceeding may be served
on either party anywhere in the world, whether within or without the
jurisdiction of any such court. Without limiting the foregoing, each party
agrees that service of process on such party as provided in Section 7 hereof
shall be deemed effective service of process on such party.

            19.  Waiver of Jury Trial. Each of the parties hereto hereby
irrevocably waives any and all right to trial by jury in any legal proceeding
arising out of or related to this agreement or the transactions contemplated
hereby.

            20.  Recapitalization, Exchanges, etc., Affecting the Company's
Capital Stock. The provisions of this Agreement shall apply to the full extent
set forth herein with respect to any and all shares of capital stock of the
Company or any successor or permitted assign of the Company (whether by merger,
consolidation, sale of assets or otherwise), or at the election of a Holder, any
person who controls any of the foregoing, which may be issued in respect of, in
exchange for or in substitution of, the Registrable Securities.

                           [Execution Page Follows]




                                       21


                                                                    Exhibit 4(1)
                                                                    ------------

            IN WITNESS WHEREOF, the undersigned have caused this Agreement to
be signed by their respective officers thereunto duly authorized as of the
date first written above.

                                    SIGA TECHNOLOGIES, INC.


                                    By: /s/ Thomas N. Konatich
                                        ----------------------
                                    Name:  Thomas N. Konatich
                                    Title: Chief Financial Officer
                                           Acting CEO



                                    MACANDREWS & FORBES HOLDINGS INC.


                                    By: /s/ Howard Gittis
                                        -------------------
                                    Title: Howard Gittis
                                           Vice Chairman






                                      S-1