EX-3(c)

                      CERTIFICATE OF DESIGNATION OF SERIES
                         AND DETERMINATION OF RIGHTS AND
                       PREFERENCES OF SERIES A CONVERTIBLE
                   PREFERRED STOCK OF SIGA TECHNOLOGIES, INC.

      SIGA Technologies, Inc., a Delaware corporation (the "Company"), acting
pursuant to ss.151 of the General Corporation Law of Delaware, does hereby
submit the following Certificate of Designation of Series and Determination of
Rights and Preferences of its Series A Convertible Preferred Stock.

      FIRST: The name of the Company is SIGA Technologies, Inc.

      SECOND: By unanimous consent of the Board of Directors of the Company
dated June 14, 2001, the following resolutions were duly adopted:

      WHEREAS the Certificate of Incorporation ("Certificate of Incorporation")
of the Company authorizes Preferred Stock consisting of 10,000,000 shares, par
value $0.0001 per share, issuable from time to time in one or more series; and

      WHEREAS the Board of Directors of the Company is authorized, subject to
limitations prescribed by law and by the provisions of Article Fourth of the
Company's Restated Certificate of Incorporation, as amended, to establish and
fix the number of shares to be included in any series of Preferred Stock and the
designation, rights, preferences, powers, restrictions and limitations of the
shares of such series; and

      WHEREAS it is the desire of the Board of Directors to establish and fix
the number of shares to be included in a new series of Preferred Stock and the
designation, rights, preferences and limitations of the shares of such new
series;

      NOW, THEREFORE, BE IT RESOLVED that pursuant to Article Fourth of the
Certificate of Incorporation there is hereby established a new series of One
Million One Hundred Thousand (1,100,000) shares of Series A Convertible
Preferred Stock of the Company (the "Series A Preferred Stock") to have the
designation, rights, preferences, powers, restrictions and limitations set forth
in a supplement of Article IV as follows:

      1.    Dividends.

            (a) The holders of the outstanding shares of Series A Preferred
      Stock shall be entitled to receive, out of any funds legally available
      therefor, dividends at the annual rate of 6% of the Original Series A
      Issue Price (as defined below) per share (subject to appropriate
      adjustment in the event of any stock dividend, stock split, combination or
      other similar recapitalization of such shares), payable in cash or, at the
      option of the Company, in shares of Series A Preferred Stock valued at the
      Liquidation Amount of such shares. Such dividends shall be payable if, as
      and when declared by the Company's Board of Directors or upon a
      liquidation, dissolution or winding up as provided in Section 2, and not
      otherwise. Such dividends shall accrue on each share of Series A

<PAGE>

      Preferred Stock from the date of original issuance of such share, whether
      or not earned or declared, but shall not compound. Such dividends shall be
      cumulative so that if such dividends in respect of any previous or current
      annual dividend period, at the annual rate specified above, shall not have
      been paid or declared and a sum sufficient for the payment thereof set
      apart, the deficiency shall first be paid before any dividend or other
      distribution shall be paid or declared and set apart for the Common Stock.

            (b) Each dividend paid in cash shall be mailed to the holders of
      record of the Series A Preferred Stock as their names and addresses appear
      on the share register of the Company or at the office of the transfer
      agent on the corresponding dividend payment date. Holders of Series A
      Preferred Stock will receive written notification from the Company or the
      transfer agent if a dividend is paid in kind, which notification will
      specify the number of shares of Series A Preferred Stock paid as a
      dividend and the recipient's aggregate holdings of Series A Preferred
      Stock as of that dividend payment date and after giving effect to the
      dividend.

      2.    Liquidation, Dissolution or Winding Up: Certain Mergers,
            Consolidations and Asset Sales.

            (a) In the event of any voluntary or involuntary liquidation,
      dissolution or winding up of the Company, the holders of shares of Series
      A Preferred Stock then outstanding shall be entitled to be paid out of the
      assets of the Company available for distribution to its stockholders, by
      reason of their ownership thereof, but prior and in preference to any
      payments made to any holders of Common Stock and any other class or series
      of capital stock of the Company which is junior to the Series A Preferred
      Stock with respect to rights to receive distributions upon liquidation an
      amount equal to $1.4375 per share (hereafter, the "Original Series A Issue
      Price") (subject to appropriate adjustment in the event of any stock
      dividend, stock split, combination or other similar recapitalization of
      such shares), plus any accrued but unpaid dividends thereon (the
      "Liquidation Amount"). If upon any such liquidation, dissolution or
      winding up of the Company the remaining assets of the Company available
      for distribution to its stockholders shall be insufficient to pay the
      holders of shares of Series A Preferred Stock the full amount to which
      they shall be entitled, the holders of shares of Series A Stock shall
      share ratably in any distribution of the remaining assets and funds of the
      Company in proportion to the respective amounts which would otherwise be
      payable in respect of the shares held by them upon such distribution if
      all amounts payable on or with respect to such shares were paid in full.

            (b) After the payment of all preferential amounts required to be
      paid to the holders of Series A Preferred Stock and any other class or
      series of capital stock ranking on parity with the Series A Preferred
      Stock upon the dissolution, liquidation or winding up of the Company, the
      holders of shares of Common Stock then outstanding shall share ratably in
      the distribution of the remaining assets and funds of the Company.

            (c) Any merger or consolidation of the Company into or with another
      Company (except one in which the holders of capital stock of the Company
      immediately prior to such merger or consolidation continue to hold at
      least fifty percent by voting


                                       2
<PAGE>

      power of the capital stock of the surviving Company after such merger or
      consolidation) or the sale of all or substantially all of the assets of
      the Company, shall be deemed to be a liquidation of the Company, and all
      consideration payable to the stockholders of the Company (in the case of a
      merger or consolidation), or all consideration payable to the Company,
      together with all other available assets of the Company (in the case of an
      asset sale), shall be distributed to the holders of capital stock of the
      Company in accordance with Subsections 2(a) and 2(b) above. The Company
      shall promptly provide to the holders of shares of Series A Preferred
      Stock such information concerning the terms of such merger, consolidation
      or asset sale and the value of the assets of the Company as may reasonably
      be requested by the holders of Series A Preferred Stock. If applicable,
      the Company shall cause the agreement or plan of merger or consolidation
      to provide for a rate at which the shares of capital stock of the Company
      are converted into or exchanged for cash, new securities or other property
      which gives effect to this provision. The amount deemed distributed to the
      holders of Series A Preferred Stock upon any such merger or consolidation
      shall be the cash or the value of the property, rights or securities
      distributed to such holders by the acquiring person, firm or other entity.
      The value of such property, rights or other securities shall be determined
      in good faith by the Board of Directors of the Company. Notwithstanding
      anything to the contrary contained in this paragraph, a holder of Series A
      Preferred Stock may elect to give effect to the conversion rights
      contained in Section 4 (or the rights contained in Sections 4(i), if
      applicable) instead of giving effect to the provisions contained in this
      subparagraph (c) with respect to the shares of Series A Preferred Stock
      owned by such holder.

      3.    Voting.

            Each holder of outstanding shares of Series A Preferred Stock shall
      be entitled to the number of votes equal to the number of whole shares of
      Common Stock into which the shares of Series A Preferred Stock held by
      such holder are then convertible (as adjusted from time to time pursuant
      to Section 4 hereof), at each meeting of stockholders of the Company (and
      written actions of stockholders in lieu of meetings) with respect to any
      and all matters presented to the stockholders of the Company for their
      action or consideration (including, without limitation, any matter voted
      on together with the holders of Common Stock). Except as provided by law,
      by any of the provisions contained herein or by the provisions
      establishing any other series of stock, holders of Series A Preferred
      Stock and of any other outstanding series of stock shall vote together
      with the holders of Common Stock as a single class.

      4.    Optional Conversion. The holders of the Series A Preferred Stock
            shall have conversion rights as follows (the "Conversion Rights"):

            (a) Right to Convert. Each share of Series A Preferred Stock shall
      be convertible, at the option of the holder thereof, at any time and from
      time to time, and without the payment of additional consideration by the
      holder thereof, into such number of fully paid and nonassessable shares of
      Common Stock as is determined by dividing $1.4375 by the Series A


                                       3
<PAGE>

      Conversion Price (as defined below) in effect at the time of conversion.
      The "Series A Conversion Price" shall initially be $1.4375. Such Series A
      Conversion Price and the rate at which shares of Series A Preferred Stock
      may be converted into shares of Common Stock shall be subject to
      adjustment as provided below.

      In the event of a liquidation of the Company, the Conversion Right shall
terminate at the close of business on the first full day preceding the date
fixed for the payment of any amounts distributable on liquidation to the holders
of Series A Preferred Stock. In the event of liquidation, the Company shall
provide to each holder of shares of Series A Preferred Stock at least 20 days
prior to the termination of the Conversion Right, notice of such event of
liquidation which notice shall include the full amounts that will be
distributable on such liquidation, as the case may be.

            (b) Fractional Shares. No fractional shares of Common Stock shall be
      issued upon conversion of the Series A Preferred Stock. In lieu of any
      fractional shares to which the holder would otherwise be entitled, the
      Company shall pay cash equal to such fraction multiplied by the then
      effective Series A Conversion Price.

            (c) Mechanics of Conversion.

                  (i) In order for a holder of Series A Preferred Stock to
            convert such shares into shares of Common Stock, such holder shall
            surrender the certificate or certificates for such shares of Series
            A Preferred Stock at the office of the transfer agent for the Series
            A Preferred Stock (or at the principal office of the Company if the
            Company serves as its own transfer agent), together with written
            notice that such holder elects to convert all or any number of the
            shares of the Series A Preferred Stock represented by such
            certificate or certificates. Such notice shall state such holder's
            name or the names of the nominees in which such holder wishes the
            certificate or certificates for shares of Common Stock to be issued.
            If required by the Company, certificates surrendered for conversion
            shall be endorsed or accompanied by a written instrument or
            instruments of transfer, in form satisfactory to the Company, duly
            executed by the registered holder or his or its attorney duly
            authorized in writing. The date of receipt of such certificates and
            notice by the transfer agent (or by the Company if the Company
            serves as its own transfer agent) shall be the conversion date (the
            "Conversion Date"). The Company shall, as soon as practicable after
            the Conversion Date, issue and deliver at such office to such holder
            of Series A Preferred Stock, or to his or its nominees, a
            certificate or certificates for the number of shares of Common Stock
            to which such holder shall be entitled, together with cash in lieu
            of any fraction of a share.

                  (ii) The Company shall at all times when the Series A
            Preferred Stock shall be outstanding, reserve and keep available out
            of its authorized but unissued stock, for the purpose of effecting
            the conversion of the Series A Preferred Stock, such number of its
            duly authorized shares of Common Stock as shall from time to time be
            sufficient to effect the conversion of all outstanding Series A
            Preferred Stock. Before taking any action which would cause an
            adjustment reducing the Series A Conversion Price below the then par
            value of the shares of Common Stock issuable upon conversion of the
            Series A Preferred Stock, the Company will take any corporate action
            which may, in the opinion of its counsel, be necessary in order that
            the Company may validly and legally issue fully paid and


                                       4
<PAGE>

            nonassessable shares of Common Stock at such adjusted Series A
            Conversion Price.

                  (iii) Upon any such conversion, no adjustment to the Series A
            Conversion Price shall be made for accrued or declared but unpaid
            dividends on the Series A Preferred Stock surrendered for conversion
            or on the Common Stock delivered upon conversion.

                  (iv) All shares of Series A Preferred Stock which shall have
            been surrendered for conversion as herein provided shall no longer
            be deemed to be outstanding and all rights with respect to such
            shares, including the rights, if any, to receive notices and to
            vote, shall immediately cease and terminate on the Conversion Date,
            except only the right of the holders thereof to receive shares of
            Common Stock in exchange therefor and payment of any dividends
            declared or accrued but unpaid thereon. Any shares of Series A
            Preferred Stock so converted shall be retired and canceled and shall
            not be reissued, and the Company (without the need for stockholder
            action) may from time to time take such appropriate action as may be
            necessary to reduce the authorized Series A Preferred Stock
            accordingly.

                  (v) The Company shall pay any and all issue and other taxes
            that may be payable in respect of any issuance or delivery of shares
            of Common Stock upon conversion of shares of Series A Preferred
            Stock pursuant to this Section 4. The Company shall not, however, be
            required to pay any tax which may be payable in respect of any
            transfer involved in the issuance and delivery of shares of Common
            Stock in a name other than that in which the shares of Series A
            Preferred Stock so converted were registered, and no such issuance
            or delivery shall be made unless and until the person or entity
            requesting such issuance has paid to the Company the amount of any
            such tax or has established, to the satisfaction of the Company,
            that such tax has been paid.

            (d) Adjustments to Conversion Price for Diluting Issues:

                  (i) Special Definitions. For purposes of this Subsection 4(d),
            the following definitions shall apply:

                        (A) "Option" shall mean rights, options or warrants to
subscribe for, purchase or otherwise acquire Common Stock or Convertible
Securities.

                        (B) "Series A Original Issue Date" shall mean the date
on which a share of Series A Preferred Stock was first issued.

                        (C) "Convertible Securities" shall mean any evidences of
indebtedness, shares or other securities directly or indirectly convertible into
or exchangeable for Common Stock.


                                       5
<PAGE>

                        (D) "Additional Shares of Common Stock" shall mean all
shares of Common Stock issued by the Company after the Series A Original Issue
Date other than:

                             (I)   Upon conversion of any
                                   Convertible Securities, or
                                   upon exercise of any Options
                                   and shares of Common Stock
                                   issued or issuable upon
                                   conversion of shares of Series
                                   A Preferred Stock.

                             (II)  shares issued as a dividend or
                                   distribution on the Series A
                                   Preferred Stock;

                             (III) shares issued by reason of a
                                   dividend, stock split,
                                   split-up or other distribution
                                   on shares of Common Stock that
                                   is covered by Subsection 4(e)
                                   or 4(f) of Sections B or C
                                   hereof; or

                             (IV)  in consideration for the
                                   acquisition (whether by merger
                                   or otherwise) by the Company
                                   of all or substantially all of
                                   the capital stock or assets of
                                   any other entity, or
                                   securities issued in
                                   consideration of any
                                   licensing, corporate
                                   partnering or strategic
                                   alliance transaction.

                  (ii) No Adjustment of Conversion Price. No adjustment in the
            number of shares of Common Stock into which the Series A Preferred
            Stock is convertible shall be made, by adjustment in the Series A
            Conversion Price thereof: (a) unless the consideration per share
            (determined pursuant to Subsection 4(d)(iv)) for an Additional Share
            of Common Stock issued or deemed to be issued by the Company is less
            than the Series A Conversion Price in effect on the date of, and
            immediately prior to, the issue of such Additional Shares, or (b) if
            prior to such issuance, the Company receives written notice from the
            holders of at least fifty percent of the then outstanding shares of
            Series A Preferred Stock, agreeing that no such adjustment shall be
            made as the result of the issuance of Additional Shares of Common
            Stock.

                  (iii) Adjustment of Conversion Price Upon Issuance of
            Additional Shares of Common Stock. In the event the Company shall at
            any time after the Series A Original Issue Date issue Additional
            Shares of Common Stock (but excluding shares issued as a stock split
            or combination as provided in Subsection 4(e) or upon a dividend or
            distribution as provided in Subsection 4(f)), without consideration
            or for a consideration per share less than the Series A Conversion
            Price in effect on the date of and immediately prior to such issue,
            then and in such event, the Series A Conversion Price shall be
            reduced, concurrently with such issue, to a price (calculated to the
            nearest cent) determined by multiplying the Series A Conversion
            Price by a fraction, (A) the numerator of which shall be (1)


                                       6
<PAGE>

the
            number of shares of Common Stock outstanding immediately prior to
            such issue plus (2) the number of shares of Common Stock which the
            aggregate consideration received or to be received by the Company
            for the total number of Additional Shares of Common Stock so issued
            would purchase at the Series A Conversion Price; and (B) the
            denominator of which shall be the number of shares of Common Stock
            outstanding immediately prior to such issue plus the number of such
            Additional Shares of Common Stock so issued; provided that, for the
            purpose of this Subsection 4(d)(iii), all shares of Common Stock
            issuable upon conversion of Convertible Securities outstanding
            immediately prior to such issue shall be deemed to be outstanding.

                  (iv) Determination of Consideration. For purposes of this
            Subsection 4(d), the consideration received by the Company for the
            issue of any Additional Shares of Common Stock shall be computed as
            follows:

                  Cash and Property: Such consideration shall:

                        (I) insofar as it consists of cash, be computed at the
                  aggregate of cash received by the Company, excluding amounts
                  paid or payable for accrued interest;

                        (II) insofar as it consists of property other than cash,
                  be computed at the fair market value thereof at the time of
                  such issue, as determined in good faith by the Board of
                  Directors; and

                        (III) in the event Additional Shares of Common Stock are
                  issued together with other shares or securities or other
                  assets of the Company for consideration which covers both, be
                  the proportion of such consideration so received, computed as
                  provided in clauses (I) and (II) above, as determined in good
                  faith by the Board of Directors.

                  (v) Multiple Closing Dates. In the event the Company shall
            issue on more than one date Additional Shares of Common Stock which
            are comprised of shares of the same series or class of Preferred
            Stock, and such issuance dates occur within a period of no more than
            120 days, then the Series A Conversion Price shall be adjusted only
            once on account of such issuances, with such adjustment to occur
            upon the final such issuance and to give effect to all such
            issuances as if they occurred on the date of the final such
            issuance.

      (e) Adjustment for Stock Splits and Combinations. If the Company shall at
      any time or from time to time after the Series A Original Issue Date
      effect a subdivision of the outstanding Common Stock, the Series A
      Conversion Price in effect immediately before that subdivision shall be
      proportionately decreased. If the Company shall at any time or from time
      to time after the Series A Original Issue Date combine the outstanding
      shares of Common Stock, the Series A Conversion Price then in effect
      immediately before the combination shall be proportionately increased. Any
      adjustment under this paragraph


                                       7
<PAGE>

      shall become effective at the close of business on the date the
      subdivision or combination becomes effective.

      (f) Adjustment for Certain Dividends and Distributions. In the event that
      the Company at any time, or from time to time after the Series A Original
      Issue Date, shall make or issue, or fix a record date for the
      determination of holders of Common Stock entitled to receive, a dividend
      or other distribution payable in additional shares of Common Stock, then
      and in each such event the Series A Conversion Price then in effect shall
      be decreased as of the time of such issuance or, in the event such a
      record date shall have been fixed, as of the close of business on such
      record date, by multiplying the Series A Conversion Price then in effect
      by a fraction:

            (i) the numerator of which shall be the total number of shares of
            Common Stock issued and outstanding immediately prior to the time of
            such issuance or the close of business on such record date, and

            (ii) the denominator of which shall be the total number of shares of
            Common Stock issued and outstanding immediately prior to the time of
            such issuance or the close of business on such record date plus the
            number of shares of Common Stock issuable in payment of such
            dividend or distribution; provided, however, that if such record
            date shall have been fixed and such dividend is not fully paid or if
            such distribution is not fully made on the date fixed therefor, the
            Series A Conversion Price shall be recomputed accordingly as of the
            close of business on such record date and thereafter such Series A
            Conversion Price shall be adjusted pursuant to this paragraph as of
            the time of actual payment of such dividends or distributions; and
            provided further, however, that no such adjustment shall be made if
            the holders of Series A Preferred Stock simultaneously receive a
            dividend or other distribution of shares of Common Stock in a number
            equal to the number of shares of Common Stock as they would have
            received if all outstanding shares of Series A Preferred Stock had
            been converted into Common Stock on the date of such event.

      (g) Adjustments for Other Dividends and Distributions. In the event that
      the Company at any time or from time to time after the Series A Original
      Issue Date, shall make or issue, or fix a record date for the
      determination of holders of Common Stock entitled to receive, a dividend
      or other distribution payable in securities of the Company other than
      shares of Common Stock, then and in each such event provision shall be
      made so that the holders of the Series A Preferred Stock shall receive
      upon conversion thereof in addition to the number of shares of Common
      Stock receivable thereupon, the amount of securities of the Company that
      they would have received had the Series A Preferred Stock been converted
      into Common Stock on the date of such event and had they thereafter,
      during the period from the date of such event to and including the
      conversion date, retained such securities receivable by them as aforesaid
      during such period giving application to all adjustments called for during
      such period under this paragraph with respect to the rights of the holders
      of the Series A Preferred Stock; and provided further, however, that no
      such adjustment shall be made if the holders of Series A Preferred Stock
      simultaneously receive a dividend or other distribution of such securities
      in an amount


                                       8
<PAGE>

      equal to the amount of such securities as they would have received if all
      outstanding shares of Series A Preferred Stock had been converted into
      Common Stock on the date of such event.

      (h) Adjustment for Reclassification, Exchange, or Substitution. If the
      Common Stock issuable upon the conversion of the Series A Preferred Stock
      shall be changed into the same or a different number of shares of any
      class or classes of stock, whether by capital reorganization,
      reclassification or otherwise (other than a subdivision or combination of
      shares or stock dividend provided for above, or a reorganization, merger,
      consolidation, or sale of assets provided for below), then and in each
      such event the holder of each such share of Series A Preferred Stock shall
      have the right thereafter to convert such share into the kind and amount
      of shares of stock and other securities and property receivable upon such
      reorganization, reclassification, or other change, by holders of the
      number of shares of Common Stock into which such shares of Series A
      Preferred Stock might have been converted immediately prior to such
      reorganization, reclassification, or change, all subject to further
      adjustment as provided herein.

      (i) Adjustment for Merger or Reorganization, etc. In case of any
      consolidation or merger of the Company with or into another Company, or
      the sale of all or a significant amount of the assets of the Company to
      another Company (other than a consolidation, merger or sale which is
      covered by Subsection 2(b)), each share of Series A Preferred Stock shall
      thereafter be convertible (or shall be converted into a security which
      shall be convertible) into the kind and amount of shares of stock or other
      securities or property to which a holder of the number of shares of Common
      Stock deliverable upon conversion of such Series A Preferred Stock would
      have been entitled upon such consolidation, merger or sale; and, in such
      case, appropriate adjustment (as determined in good faith by the Board of
      Directors) shall be made in the application of the provisions in this
      Section 4 set forth with respect to the rights and interest thereafter of
      the holders of the Series A Preferred Stock, to the end that the
      provisions set forth in this Section 4 (including provisions with respect
      to changes in and other adjustments of the Series A Conversion Price)
      shall thereafter be applicable, as nearly as reasonably may be, in
      relation to any shares of stock or other property thereafter deliverable
      upon the conversion of the Series A Preferred Stock. Notwithstanding
      anything to the contrary contained herein, each holder of shares of Series
      A Preferred Stock shall have the right to elect to give effect to the
      conversion rights contained in Section 4 (or the rights contained in
      Sections 2(c), if applicable) instead of giving effect to the provisions
      contained in this paragraph (i) with respect to the shares of Series A
      Preferred Stock owned by such holder.

      (j) No Impairment. The Company will not, by amendment of its Certificate
      of of Incorporation or through any reorganization, transfer of assets,
      consolidation, merger, dissolution, issue or sale of securities or any
      other voluntary action, avoid or seek to avoid the observance or
      performance of any of the terms to be observed or performed hereunder by
      the Company, but will at all times in good faith assist in the carrying
      out of all the provisions of this Section 4, and in the taking of all such
      action as may be necessary or appropriate in order to protect the
      Conversion Rights of the holders of the Series A Preferred Stock against
      impairment.


                                       9
<PAGE>

      (k) Certificate as to Adjustments. Upon the occurrence of each adjustment
      or readjustment of the Series A Conversion Price pursuant to this Section
      4, the Company shall, at its expense, promptly compute such adjustment or
      readjustment in accordance with the terms hereof and furnish to each
      holder of Series A Preferred Stock a certificate setting forth such
      adjustment or readjustment and showing in detail the facts upon which such
      adjustment or readjustment is based. The Company shall, upon the written
      request at any time of any holder of Series A Preferred Stock, furnish or
      cause to be furnished to such holder a similar certificate setting forth
      (i) such adjustments and readjustments, (ii) the Series A Conversion Price
      then in effect, and (iii) the number of shares of Common Stock and the
      amount, if any, of other property which then would be received upon the
      conversion of Series A Preferred Stock.

      (l) Notice of Record Date. In the event:

            (i) that the Company declares a dividend (or any other distribution)
      on its Common Stock payable in Common Stock or other securities of the
      Company;

            (ii) that the Company subdivides or combines its outstanding shares
      of Common Stock;

            (iii) of any reclassification of the Common Stock (other than a
      subdivision or combination of its outstanding shares of Common Stock or a
      stock dividend or stock distribution thereon), or of any consolidation or
      merger of the Company into or with another Company, or of the sale of all
      or a significant amount of the assets of the Company; or

            (iv) of the involuntary or voluntary dissolution, liquidation or
      winding up of the Company then the Company shall cause to be filed at its
      principal office or at the office of the transfer agent of the Series A
      Preferred Stock, and shall cause to be mailed to the holders of the Series
      A Preferred Stock at their last addresses as shown on the records of the
      Company or such transfer agent, at least ten days prior to the date
      specified in (A) below or twenty days before the date specified in (B)
      below, a notice stating

                  (A) the record date of such dividend, distribution,
            subdivision or combination, or, if a record is not to be taken, the
            date as of which the holders of Common Stock of record to be
            entitled to such dividend, distribution, subdivision or combination
            are to be determined, or

                  (B) the date on which such reclassification, consolidation,
            merger, sale, dissolution, liquidation or winding up is expected to
            become effective, and the date as of which it is expected that
            holders of Common Stock of record shall be entitled to exchange
            their shares of Common Stock for securities or other property
            deliverable upon such reclassification, consolidation, merger, sale,
            dissolution or winding up.

      5. Mandatory Conversion.


                                       10
<PAGE>

            (a) Each share of Series A Preferred Stock shall automatically be
      converted into shares of Common Stock at its then effective Conversion
      Price at any time upon the written consent of the holders of a majority of
      the shares of Series A Preferred Stock then outstanding (the date of such
      closing or consent, the "Mandatory Conversion Date").

            (b) All holders of record of shares of Series A Preferred Stock
      shall be given written notice of the Mandatory Conversion Date and the
      place designated for mandatory conversion of all such shares of Series A
      Preferred Stock pursuant to this Section 5. Such notice need not be given
      in advance of the occurrence of the Mandatory Conversion Date. Such notice
      shall be sent by first class or registered mail, postage prepaid, to each
      record holder of Series A Preferred Stock, at such holder's address last
      shown on the records of the transfer agent for such Series A Preferred
      Stock (or the records of the Company, if it serves as its own transfer
      agent). Upon receipt of such notice, each holder of shares of Series A
      Preferred Stock shall surrender his or its certificate or certificates for
      all such shares to the Company at the place designated in such notice, and
      shall thereafter receive certificates for the number of shares of Common
      Stock to which such holder is entitled pursuant to this Section 5. On the
      Mandatory Conversion Date, all rights with respect to the Series A
      Preferred Stock so converted, including the rights, if any, to receive
      notices and vote (other than as a holder of Common Stock) will terminate,
      except only the rights of the holders thereof, upon surrender of their
      certificate or certificates therefor, to receive certificates for the
      number of shares of Common Stock into which such Series A Preferred Stock
      have been converted, and, in each case, payment of any declared or accrued
      but unpaid dividends thereon. If required by the Company, certificates
      surrendered for conversion shall be endorsed or accompanied by written
      instrument or instruments of transfer in form satisfactory to the Company,
      duly executed by the registered holder or by his or its attorney duly
      authorized in writing. As soon as practicable after the Mandatory
      Conversion Date and the surrender of the certificate or certificates for
      Series A Preferred Stock, the Company shall issue and deliver to such
      holder, or on their written order, a certificate or certificates for the
      number of full shares of Common Stock issuable upon such conversion in
      accordance with the provisions hereof, and cash as provided in Subsection
      4(b) in respect of any fraction of a share of Common Stock otherwise
      issuable upon such conversion.

            (c) All certificates evidencing shares of Series A Preferred Stock
      which are required to be surrendered for conversion in accordance with the
      provisions hereof shall, from and after the Mandatory Conversion Date, be
      deemed to have been retired and canceled, and the shares of Series A
      Preferred Stock represented thereby converted into Common Stock for all
      purposes, notwithstanding the failure of the holder or holders thereof to
      surrender such certificates on or prior to such date. The Company may
      thereafter take such appropriate action (without the need for stockholder
      action) as may be necessary to reduce the authorized Series A Preferred
      Stock accordingly.

      IN WITNESS WHEREOF, the Company has caused this Certificate to be executed
by its Chief Executive Officer and attested to by its Secretary this 27th day of
June 2001.


                                       11
<PAGE>

                                                     SIGA TECHNOLOGIES, INC.


                                                     By:
                                                          ----------------------
                                                           Name:
                                                           Title:

ATTEST:

----------------------
Name:
Title:  Secretary


                                       12