Document:

<PAGE>

                                                                    Exhibit 10.5

NEITHER THIS WARRANT NOR ANY OF THE SECURITIES ISSUABLE HEREUNDER NOR ANY
AMERICAN DEPOSITARY SHARES REPRESENTING THE SECURITIES ISSUABLE HEREUNDER HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES
ACT"), AND NONE OF THEM MAY BE OFFERED, SOLD, TRANSFERRED, ASSIGNED NOR
HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH RESPECT
TO SUCH SECURITIES UNDER THE SECURITIES ACT AND APPLICABLE STATE SECURITIES LAW
OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH
REGISTRATION IS NOT REQUIRED.

                                 AMENDED AND RESTATED WARRANT
                                 to Purchase [_________] Ordinary Shares of
                                 SENETEK PLC

                                 Issued:  April 14, 1999
Series C                         Expires: April 14, 2009
NO. [__]

     This Warrant amends and restates in its entirety the Warrant issued to
Holder (as defined below) to purchase the same number of Ordinary Shares (as
defined below) set forth above issued on April 14, 1999 and amended on January
22, 2001.  This Warrant certifies that [__________________________________] or
its registered and permitted successors or assigns ("[__________]" or the
"Holder"), is entitled to, subject to the terms set forth below, purchase from
SENETEK PLC, a corporation organized under the laws of England (the "Company"),
from time and time up to [________________________________________________]
([____________]) duly authorized, validly issued, fully paid and nonassessable
Ordinary Shares (as such number may be adjusted pursuant to Section 4(a) and
Section 5 herein) which may be exchanged for American Depositary Shares ("ADS")
represented by American Depositary Receipts ("ADR") (the Ordinary Shares of the
Company, including any shares into which it may be changed, reclassified, or
converted, are herein referred to as the "Ordinary Shares").  This Warrant is
one of the Series C Warrants (the "Warrants") issued pursuant to Section 2 of
the Securities Purchase Agreement (the "Securities Purchase Agreement"), dated
as of April 14, 1999, by and between the Company, Silver Creek Investments,
Ltd., Bomoseen Investments, Ltd., Dandelion Investments, Ltd. and Elstree
Holdings, Ltd.  The Ordinary Shares issuable upon exercise of the Warrants (and
any other or additional shares, securities or property that may hereafter be
issuable upon exercise of the Warrants) are sometimes referred to herein as the
"Warrant Shares," and the maximum number of shares so issuable under this
Warrant is sometimes  referred to as the "Aggregate Number" (as such number may
be increased or decreased as more fully set forth herein).
<PAGE>

     This Warrant is subject to the following provisions, terms and conditions:

Section 1.  Exercise of Warrant.
            -------------------

     (a)  To exercise this Warrant in whole or in part, the Holder shall deliver
to the Company at its principal office located at 620 Airpark Road, Napa,
California 94558, (A) a written notice, in substantially the form of the
Exercise Notice attached hereto as Exhibit 1, of the Holder's election to
                                   ---------
exercise this Warrant, which notice shall specify the number of Warrant Shares
to be purchased, (B) (i) cash, money order, certified check or wire transfer of
immediately available funds payable to the Company, in an amount equal to the
Exercise Price (as defined below) multiplied by the number of Warrant Shares
                                  ----------
being purchased, or (ii) a copy of an instrument representing outstanding
principal amount of indebtedness of the Company owed to the Holder, accompanied
by a notice stating the Holder's intent to exercise this Warrant, in whole or in
part, by the reduction of the amount of indebtedness stated in the notice and
represented by the instrument in an amount equal to the Exercise Price
multiplied by the number of Warrant Shares being purchased, and (C) this
Warrant.  The Company shall as promptly as practicable, and in any event within
ten (10) Business Days thereafter, execute and deliver or cause to be executed
and delivered, in accordance with such notice, a certificate or certificates
representing the aggregate number of Warrant Shares specified in such notice.
The stock certificate or certificates so delivered shall be in such
denominations as may be specified in such notice and shall be issued in the name
of the Holder or such other name as shall be designated in such notice.  Such
certificate or certificates shall be deemed to have been issued and the Holder
or any other person so designated to be named therein shall be deemed for all
purposes to have become a Holder of record of such shares immediately prior to
the close of business on the date such notice is received by the Company as
aforesaid.  If this Warrant shall have been exercised only in part, the Company
shall, at the time of delivery of said stock certificate or certificates,
deliver to the Holder a new Warrant evidencing the rights of the Holder to
purchase the remaining Ordinary Shares called for by this Warrant, which new
Warrant shall in all other respects be identical to this Warrant, or, at the
request of the Holder, appropriate notation may be made on this Warrant and the
same returned to the Holder.  The Company shall pay all expenses, taxes (except
United Kingdom stamp tax duties) and other charges payable in connection with
the preparation, issue and delivery of such certificates and new Warrants,
except that in case such stock certificates or new Warrants shall be registered
in a name or names other than the name of the Holder, funds sufficient to pay
all stock transfer taxes that are payable upon the issuance of such stock
certificates or new Warrants shall be paid by the Holder at the time of
delivering the notice of exercise mentioned above.

     (b)  All Ordinary Shares issued upon the exercise of this Warrant shall be
validly issued, fully paid and nonassessable and free from all preemptive rights
of any stockholder, and from all taxes, liens and charges with respect to the
issue thereof (other than United Kingdom stamp duty taxes and any other transfer
taxes) and, if any Ordinary Shares are then listed on a national securities
exchange (as defined in the Securities Exchange Act of 1934, as amended) or
quoted on an automated quotation system, shall be listed or quoted thereon, as
the case may be, to the extent permissible under the rules of such exchange and
not prohibited by law, it being understood that such listing does not bear upon
the transferability of such shares under the Act

                                       2
<PAGE>

and the other provisions of this Agreement.

     (c)  The Company shall not be required upon any exercise of this Warrant to
issue a certificate representing any fraction of an Ordinary Share, but, in lieu
thereof, shall pay to the Holder cash in an amount equal to a corresponding
fraction (calculated to the nearest 1/100 of a share) of the Fair Market Value
(as defined below) of one Ordinary Share on the Business Day immediately prior
to the date of receipt by the Company of notice of exercise of this Warrant.

     (d)  The Company shall pay all depositary fees payable to the depositary
and all stamp duty reserve taxes due to Inland Revenue in respect of the
issuance of American Depositary Shares or American Depositary Receipts in
respect of Ordinary Shares issued upon exercise of the Warrant.

Section 2.  Terms and Conditions of Warrants.
            --------------------------------

     (a)  Exercise. Warrants to purchase 355,197 (as adjusted in accordance with
the principles of Section 4(a) or Section 5 hereof) Ordinary Shares shall be
exercisable at any time, and from time to time, on or after the date hereof (the
"Exercise Date"), and shall expire at 11:59 p.m., New York City time, on April
14, 2009 (the "Expiration Date").

     (b)  Purchase Price. Subject to the provisions of Sections 5 and 6 hereof,
the purchase price per Ordinary Share shall be $1.00 (the "Exercise Price").

     (c)   Restrictions on Transfer and Registration Rights.

          (i)  Each certificate for any Warrant Shares issued upon the exercise
of this Warrant, and each certificate issued upon the transfer of any such
Warrant Shares and each American Depositary Receipt representing American
Depositary Shares (except as otherwise permitted by this Section 2(c)) shall be
stamped or otherwise imprinted with a legend in substantially the following
form:

     THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
     REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
     "ACT"), AND MAY NOT BE OFFERED, SOLD, TRANSFERRED, ASSIGNED OR
     HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT
     WITH RESPECT TO SUCH SECURITIES UNDER THE ACT AND REGISTRATION OR
     QUALIFICATION UNDER APPLICABLE STATE SECURITIES LAW OR AN OPINION
     OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH
     REGISTRATION AND QUALIFICATION IS NOT REQUIRED.

          (ii) The restrictions imposed by this Section 2(c) upon the
transferability of Warrants and Warrant Shares and related American Depositary
Shares shall cease and terminate as to any particular Warrants, Warrant Shares
or related American Depositary Shares, (a) when

                                       3
<PAGE>

such securities shall have been effectively registered under the Securities Act
and disposed of in accordance with the registration statement covering such
securities, or (b) when in the reasonable opinion of counsel for the Company
such restrictions are no longer required in order to comply with the Securities
Act of 1993, as amended (the "Securities Act"). Whenever such restrictions shall
terminate as to any Warrants, Warrant Shares or related American Depositary
Shares, the Holder thereof shall be entitled to receive from the Company,
without expense, new certificates of like tenor not bearing the restrictive
legend set forth in Section 2(c)(i).

     (d)  Investment Representation. The Holder, by acceptance hereof,
represents as of the date hereof, as follows:

          (i)   The Warrant Shares issuable upon exercise of the Warrants
(collectively, the "Acquired Securities") will be acquired for investment for
the Holder's own account, not as a nominee or agent, and not with a view to the
resale or distribution of any part of the Acquired Securities in contravention
of applicable law, and that the Holder has no present intention of selling,
granting any participation in, or otherwise distributing the same.  The Holder
does not have any contract, undertaking, agreement or arrangement with any
person to sell, transfer or grant participations to such person or to any third
person in or with respect to any of the Acquired Securities.

          (ii)  The Holder is and upon the acquisition of Acquired Securities
upon exercise of the Warrants will be an "accredited investor" within the
meaning of Rule 501 of Regulation D of the rules and regulations of the
Securities and Exchange Commission under the Securities Act. The Holder has not
been organized for the purposes of acquiring the Acquired Securities.

          (iii) The Holder understands that the Acquired Securities it may
acquire as contemplated by this Warrant are "restricted securities" within the
meaning of Rule 144 under the Securities Act ("Rule 144") inasmuch as they will
be acquired from the Company in a transaction not involving a public offering
and that under the federal securities laws and applicable regulations such
Acquired Securities may be resold without registration under the Securities Act
only in certain limited circumstances.  In this connection, the Holder
represents that it is familiar with Rule 144 and understands the resale
limitations imposed thereby and by the Securities Act.  The Holder acknowledges
that its investment in the Acquired Securities may be an illiquid investment
requiring the Holder to bear the economic risk of the investment for an
indefinite period; and

          (iv)  Without in any way limiting the representations set forth in
this Section 2(d), the Holder agrees not to make any disposition of all or any
portion of the Acquired Securities unless and until the transferee has agreed in
writing for the benefit of the Company to be bound by the terms of this Warrant
(provided that such Holder is making such disposition in a transaction other
than pursuant to Rule 144 or under an effective registration statement under the
Securities Act and in accordance with any applicable state securities laws), and
(A) the Holder shall have notified the Company of the proposed disposition, and
(B) if requested by the Company, the Holder shall have furnished the Company
with an opinion of counsel, in form and

                                       4
<PAGE>

substance reasonably satisfactory to the Company, rendered by a law firm
experienced in matters involving the sale of securities under federal and state
securities laws, that such disposition will not require registration of the
Acquired Securities under the Securities Act or registration or qualification
under any state securities or "blue sky" law.

     In the event certificates for Ordinary Shares are delivered upon the
exercise of this Warrant, the Company may cause a legend or legends to be placed
on such certificates to make appropriate reference to such foregoing
representations and to restrict transfer in the absence of compliance with
applicable federal or state securities laws.

Section 3.  Transfer, Division and Combination.  The Company agrees to maintain
            ----------------------------------
at its offices in Napa, California, books for the registration and transfer of
this Warrant and, subject to the provisions of Section 2 hereof, this Warrant
and all rights hereunder are transferable, in whole or in part, on such books at
such office, upon surrender of this Warrant at such office, together with a
written assignment of this Warrant duly executed by the Holder or his agent or
attorney and funds sufficient to pay any stock transfer taxes payable upon the
making of such transfer.  Upon such surrender and payment, the Company shall
execute and deliver a new Warrant or Warrants in the name of the assignee or
assignees and in the denominations specified in such instrument of assignment,
and this Warrant shall promptly be canceled.  Notwithstanding the foregoing, a
Warrant may be exercised by a new Holder for the purchase of Ordinary Shares
without having a new Warrant issued if Holder shall otherwise have complied with
the foregoing provisions of this Section 3 and the applicable provisions of
Section 2 hereof.  All of the provisions of this Section 3 are subject to the
provisions of Sections 2 above.  This Warrant may be divided or combined with
other Warrants upon surrender hereof and of any Warrant or Warrants with which
this Warrant is to be combined, together with a written notice specifying the
names and denominations in which the new Warrant or Warrants are to be issued,
signed by the holders thereof or their respective duly authorized agents or
attorneys.  The Company shall execute and deliver a new Warrant or Warrants
exchangeable for the Warrant or Warrants to be divided or combined in accordance
with such notice.

Section 4.  Successor; Taxes.
            ----------------

     (a)  Successor Company. The obligations of the Company under this Warrant
shall be binding upon any successor company or organization resulting from the
merger, consolidation or other reorganization of the Company, or upon any
successor company or organization succeeding to substantially all of the assets
and business of the Company. The Company agrees that it will make appropriate
provision for the preservation of Holder's rights under this Warrant in any
agreement or plan which it may enter into or adopt to effect any such merger,
consolidation, reorganization or transfer of assets.

     (b)  Taxes on Conversion.  The issuance of certificates for Warrant Shares
upon the exercise of this Warrant shall be made without charge to the Holder
exercising this Warrant for any issue or stamp tax in respect of the issuance of
such certificates, and such certificates shall be issued in the respective names
of, or in such names as may be directed by, the holder; provided, however, that
                                                        --------  -------
the Company shall not be required to pay any tax that may be payable in respect
of

                                       5
<PAGE>

any transfer involved in the issuance and delivery of any such certificate in a
name other than that of the Holder, and the Company shall not be required to
issue or deliver such certificates unless or until the person or persons
requesting the issuance thereof shall have paid to the Company the amount of
such tax or shall have established to the satisfaction of the Company that such
tax has been paid.

    (c)   Withholding Taxes.

          (i)   Except to the extent otherwise required by law, the Company will
not withhold United States or United Kingdom withholding taxes from payments to
be made to holders of Warrants if such holders (a) are corporations organized
under the laws of a jurisdiction outside the United States or United Kingdom or
are otherwise persons not resident in the United States or United Kingdom for
U.S. federal income tax purposes or United Kingdom tax purposes, and (b) provide
the Company, upon the Company's reasonable request, with one or more of Internal
Revenue Service Form W-8, Form 4224 or other applicable form, certificate or
document prescribed by the Internal Revenue Service of the United States or
Inland Revenue of the United Kingdom certifying as to such holders' entitlement
to an exemption from any such withholding requirements.

          (ii)  Except to the extent otherwise required by law, the Company will
not withhold United States or United Kingdom withholding taxes from payments to
be made to holders of Warrants in excess of an applicable treaty rate if such
holders (a) are corporations organized under the laws of a jurisdiction outside
the United States or United Kingdom or are otherwise persons not resident in the
United States or United Kingdom for U.S. federal income tax purposes or United
Kingdom tax purposes, and (b) provide the Company upon the Company's reasonable
request, with one or more of certification of their residence address, Internal
Revenue Service Form 1001 or other applicable form, certificates or documents
certifying as to such holders' entitlement to a reduced rate of withholding
under any such withholding requirements.

          (iii) Except to the extent otherwise required by law, neither Section
4(c)(1) nor Section 4(c)(ii) hereof shall require the Company to apply an
exemption or reduced rate of withholding during any period when it shall have
received notice or has knowledge that (a) the residence or other information
previously provided on any applicable form, certificate or document is incorrect
and no corrected form, certificate or document as applicable has been provided
to the Company, or (b) of any other information which would render such
exemption or reduced rate inapplicable.

          (iv)  Notwithstanding the preceding Sections 4(c)(i) and 4(c)(ii), if
the Company is required by law to withhold from amounts otherwise payable to a
holder of Warrants, whether by reason of a change in law or applicable treaty,
or because the applicable treaty withholding rate is greater than zero or by
reason of the failure of a holder of Warrants to provide a valid certification
or form, the Company shall withhold the amounts required to be withheld.
Amounts so withheld with respect to a holder in accordance with this Section 4
shall be treated as distributed to such holder for all purposes of this Warrant.

                                       6
<PAGE>

Section 5.  Adjustments to Aggregate Number.    The Aggregate Number shall be
            -------------------------------
subject to adjustment from time to time as follows and thereafter as adjusted
shall be deemed to be the Aggregate Number hereunder.

     (a)  Reorganization, Reclassification, Consolidation, Merger or Sale. If
any capital reorganization or reclassification of the Company, or any
consolidation or merger of the Company with another person, or the sale,
transfer or lease of all or substantially all of its assets to another person
shall be effected in such a way that holders of Ordinary Shares shall be
entitled to receive stock, securities or assets with respect to or in exchange
for their shares, then provision shall be made, in accordance with this Section
5, whereby the Holder hereof shall thereafter have the right to purchase and
receive, upon the basis and upon the terms and conditions specified in this
Warrant and in addition to or in exchange for, as applicable, the Warrant Shares
subject to this Warrant immediately theretofore purchasable and receivable upon
the exercise of the rights represented hereby, such securities or assets as
would have been issued or payable with respect to or in exchange for the
Aggregate Number immediately theretofore purchasable and receivable upon the
exercise of the rights represented hereby if exercise of the Warrant has
occurred immediately prior to such reorganization, reclassification,
consolidation, merger or sale. The Company will not effect any such
consolidation, merger, sale, transfer or lease unless prior to the consummation
thereof the successor entity (if other than the Company) resulting from such
consolidation or merger or the entity purchasing or leasing such assets shall
assume by written instrument (1) the obligation to deliver to such Holder such
securities or assets as, in accordance with the foregoing provisions, such
Holder may be entitled to purchase, and (2) all other obligations of the Company
under this Warrant. The provisions of this Section 5(a) shall similarly apply to
successive consolidations, mergers, exchanges, sales, transfers or leases.

     (b)  Distributions.  If at any time or from time to time the Company shall
take a record of the holders of its Ordinary Shares for the purpose of entitling
them to receive or pays any dividend or other distribution to holders of
Ordinary Shares (collectively, a "Distribution") of:

          (i)   cash,

          (ii)  any evidences of its indebtedness (other than securities
     convertible into Ordinary Shares ("Convertible Securities")), any shares of
     its capital stock (other than additional Ordinary Shares or Convertible
     Securities) or any other securities or property of any nature whatsoever
     (other than cash), or

          (iii) any options or warrants or other rights to subscribe for or
     purchase any of the following:  any evidences of its indebtedness (other
     than Convertible Securities), any shares of its capital stock (other than
     additional Ordinary Shares or Convertible Securities) or any other
     securities or property of any nature whatsoever,

then the holder of this Warrant shall be entitled to receive upon the exercise
hereof at any time on or after the taking of such record the number of Ordinary
Shares to be received upon exercise of such Warrant determined as stated herein
and, in addition and without further payment, the cash,

                                       7
<PAGE>

stock, securities, other property, options, warrants and/or other rights to
which such holder or holders would have been entitled by way of the Distribution
and subsequent dividends and distributions if such Holder (x) had exercised such
Warrants immediately prior to such Distribution, and (y) had retained the
Distribution in respect of the Ordinary Shares and all subsequent dividends and
distributions of any nature whatsoever in respect of any stock or securities
paid as dividends and distributions and originating directly or indirectly from
such Ordinary Shares. A reclassification of the Ordinary Shares into any other
class of stock shall be deemed a distribution by the Company to the holders of
its Ordinary Shares or such shares of such other class of stock within the
meaning of paragraph (c) of this Section 5 and, if the outstanding Ordinary
Shares shall be changed into a larger or smaller number of Ordinary Shares as a
part of such reclassification, such event shall be deemed a subdivision or
combination, as the case may be, of the outstanding Ordinary Shares within the
meaning of paragraph (c) of this Section 5. If the securities to be distributed
by the Company involve rights, warrants, options or any other form of
Convertible Securities and the right to exercise or convert such securities
would expire in accordance with its terms prior to the exercise of this Warrant,
then the terms of such securities shall provide that such exercise or
convertibility right shall remain in effect until 30 days after the date the
Holder of this Warrant receives such securities pursuant to the exercise hereof.

     (c)  In addition to those adjustments set forth in Sections 5(a) and 5(b),
but without duplication of the adjustments to be made under such Sections 5(a)
and 5(b) and Section 6, if the Company:

          (i)   takes a record of the holders of its Ordinary Shares for the
     purpose of entitling them to receive or pays a dividend payable in, or
     other distribution of, Ordinary Shares;

          (ii)  subdivides its outstanding shares of Ordinary Shares into a
     greater number of Ordinary Shares;

          (iii) combines its outstanding Ordinary Shares into a lesser number
     of shares of Ordinary Shares; and/or

          (iv)  makes a distribution on its Ordinary Shares in shares of its
     capital stock other than Ordinary Shares,

then (A) the Aggregate Number in effect immediately prior thereto shall be
adjusted so that the holder or holders of this Warrant shall thereafter be
entitled to receive, upon exercise hereof, the number of Ordinary Shares or
other securities of the Company (such other securities thereafter enjoying the
rights of Warrant Shares under this Warrant) that such Holder would have owned
or have been entitled to receive after the occurrence of such event had such
Warrants been exercised immediately prior to the occurrence of such event or the
record date with respect thereto, and (B) the Exercise Price shall (until
another such event) be adjusted to equal (calculated to the nearest full cent)
the quotient derived by dividing (x) the Aggregate Number in effect immediately
prior to such adjustment multiplied by the Exercise Price in effect immediately
prior to such

                                       8
<PAGE>

adjustment, divided by (y) the Aggregate Number in effect after adjustment
pursuant to this Section 5(c).

Section 6.  Adjustment to Exercise Price.
            ----------------------------

     (a)  If the Company shall issue or sell any Ordinary Shares at a price
which is less than the Exercise Price, then the Exercise Price in effect
immediately prior thereto shall be adjusted immediately so that the Exercise
Price thereafter shall equal the price per Ordinary Share at which such Ordinary
Shares described in this Section 6(a) were issued. The provisions of this
paragraph (a) shall not apply to any issuance of additional Ordinary Shares for
which an adjustment is provided under Sections 5(a), (b) or (c).

     (b)  If the Company shall take a record of the holders of its Ordinary
Shares for the purpose of entitling them to receive a distribution of, or shall
in any manner issue or sell, any warrants or other rights to subscribe for or
purchase (x) any shares of Ordinary Shares or (y) any Convertible Securities,
whether or not the rights to subscribe, purchase, exchange or convert thereunder
are immediately exercisable, at a purchase price per Ordinary Share which is
less than the Exercise Price, then the Exercise Price in effect immediately
prior thereto shall be adjusted immediately so that the Exercise Price
thereafter shall equal the consideration for which such Ordinary Shares or
Ordinary Shares subject to Convertible Securities described in this Section 6(b)
were issued. For purposes of this Section 6(b), the consideration for any
additional Ordinary Shares issuable pursuant to any warrants or other rights to
subscribe for or purchase the same or for any additional Ordinary Shares
issuable pursuant to Convertible Securities subject to any warrants or other
rights shall be the consideration received or receivable by the Company for
issuing such warrants or other rights, plus the additional consideration payable
to the Company upon the exercise of such warrants or other rights and upon the
exercise of the Convertible Securities, as the case may be.

     (c)  If the Company shall take a record of the holders of its Ordinary
Shares for the purpose of entitling them to receive a distribution of or shall
in any manner issue or sell Convertible Securities, whether or not the rights to
exchange or convert thereunder are immediately exercisable, at a purchase price
per Ordinary Share which is less than the Exercise Price, then the Exercise
Price in effect immediately prior thereto shall be adjusted immediately so that
the Exercise Price thereafter shall equal the purchase price per Ordinary Share
issuable pursuant to the terms of any Convertible Securities. For purposes of
this Section 6(c), the purchase price per Ordinary Share issuable pursuant to
the terms of any Convertible Security shall be the consideration received or
receivable by the Company for issuing the Convertible Security, plus the
additional consideration, if any, payable to the Company upon the purchase of
the Ordinary Share pursuant to the Convertible Security.

                                       9
<PAGE>

Section 7.  General Provisions Regarding Adjustments to Aggregate Number or
            ---------------------------------------------------------------
            Exercise Price.
            --------------

     (a)    The following provisions shall be applicable to the making of
adjustments of (i) the Aggregate Number as provided in Section 5 or (ii) the
Exercise Price as provided in Section 6:

            (i)     The sale or other disposition of any issued Ordinary Shares
     owned or held by or for the account of the Company shall be deemed an
     issuance thereof for the purposes of Sections 5 and 6.

            (ii)    The adjustments required by Sections 5 and 6 shall be made
     whenever and as often as any specified event requiring an adjustment shall
     occur, except as expressly provided herein. For the purpose of any
     adjustment, any specified event shall be deemed to have occurred at the
     close of business on the date of its occurrence.

            (iii)   In computing adjustments under Sections 5 and 6, fractional
     interests in Ordinary Shares shall be taken into account to the nearest
     one-thousandth (.001) of a share and shall be aggregated until they equal
     one whole share.

            (iv)    If the Company shall take a record of the holders of its
     Ordinary Shares for an action described in Sections 5 or 6 hereof, but
     abandons its plan to take such action prior to effecting such action, then
     no adjustment shall be required by reason of the taking of such record.

            (v)     Notwithstanding anything herein to the contrary, no
     adjustment shall be made to the Aggregate Number or Exercise Price as a
     result of adjustments to the Aggregate Number or Exercise Price as defined
     in any Warrants issued to the Holder on the date hereof.

            (vi)    Upon the expiration or termination of any of the warrants or
     other rights or options referred to in Section 6(b) above or the
     Convertible Securities referred to in Section 6(b) or 6(c) above, the
     Exercise Price after the expiration or termination of any such warrants,
     rights, options or Convertible Securities without any exercise or
     conversion thereof, the issuance of which caused an adjustment to the
     Exercise Price, shall be readjusted to such Exercise Price prior to the
     adjustment made upon the issuance of such warrants, rights, options or
     Convertible Securities.

            (vii)   In case of the issuance at any time of any additional
     Ordinary Shares or Convertible Securities in payment or satisfaction of any
     dividend upon any class of stock other than Ordinary Shares, the Company
     shall be deemed to have received for such additional Ordinary Shares or
     Convertible Securities a consideration equal to the amount of such dividend
     so paid or satisfied.

            (viii)  No adjustment to the Aggregate Number or Exercise Price
     shall be made for issuances of (A) Options granted under the Company's No.
     1 Executive Share Option

                                       10
<PAGE>

     Scheme or No. 2 Executive Share Option Scheme or any other employee, non-
     executive director or consultant share option scheme approved by the
     Company's directors, and Ordinary Shares issuable or issued upon exercise
     of such options, (B) Ordinary Shares issued or issuable upon (x) the
     exercise of options, warrants or rights to subscribe for or purchase
     Ordinary Shares, or (y) the conversion or exchange of securities
     convertible into or exchangeable for Ordinary Shares or options, warrants
     or rights to subscribe for or purchase Ordinary Shares, in each case only
     to the extent outstanding on the date of issuance of this Warrant and (C)
     Ordinary Shares issued pursuant to a transaction described in Section 5(a)
     or (b) hereof.

            (ix)    No adjustment of the Exercise Price shall be made in an
     amount less than one cent per share, provided that any adjustments which
     are not required to be made by reason of this sentence shall be carried
     forward and shall be taken into account in any subsequent adjustment made.

     (b)    If any event occurs as to which the provisions of Section 5 or
Section 6 are not strictly applicable but the lack of any provision for the
exercise of the rights of a holder or holders of Warrants would not fairly
protect the purchase rights of such holder or holders of Warrants in accordance
with the essential intent and principles of such provisions, then the Company
shall appoint a firm of independent certified public accountants in the United
States (which may be the regular outside auditors of the Company) of recognized
national standing in the United States satisfactory to the Holder, which shall
give its opinion as to the adjustments, if any, necessary to preserve, without
dilution, on a basis consistent with the essential intent and principles
established in the provisions of Section 5 or Section 6, the exercise rights of
the holders of Warrants. Upon receipt of such opinion, the Company shall
forthwith make the adjustments described therein.

     (c)    Within 45 days after the end of each fiscal quarter during which an
event occurred that resulted in an adjustment pursuant to Section 5 or Section
6, the Company shall cause to be promptly mailed to each holder of Warrants (and
upon the exercise of any Warrants to the exercising holder) by first-class mail,
postage prepaid, notice of each adjustment or adjustments to the Aggregate
Number or Exercise Price, as the case may be, effected since the date of the
last such notice and a certificate of the Company's Chief Financial Officer or,
in the case of any such notice delivered within 45 days after the end of a
fiscal year, a firm of independent public accountants in the United States
selected by the Company and acceptable to a majority in interest of the holders
of the Warrants (who may be the regular outside auditors employed by the
Company), in each case, setting forth the Aggregate Number or Exercise Price, as
the case may be, after such adjustment, a brief statement of the facts requiring
such adjustment and the computation by which such adjustment was made. The fees
and expenses of such accountants shall be paid by the Company.

Section 8.  Covenant to Reserve Shares of Ordinary Shares.  The Company
            ---------------------------------------------
covenants and agrees that it will at all times reserve and set apart and have,
free from preemptive rights, a number of shares of authorized but unissued
Ordinary Shares sufficient to enable it at any time to fulfill all its
obligations hereunder.  The issuance of such shares has been duly and validly

                                       11
<PAGE>

authorized, and when issued and sold in accordance with the Warrants, such
shares will be duly and validly issued, fully paid and nonassessable.

Section 9.  Reduction in Number of Warrant Shares.  This Warrant is one of a
            -------------------------------------
number of Series C Warrants to purchase an aggregate of Ordinary Shares issued
pursuant to the terms of the Settlement Agreement (as defined in the Securities
Purchase Agreement) in connection with the concurrent issuance by the Company of
Settlement Notes (as defined in the Securities Purchase Agreement) in the
aggregate principal amount of $2,388,750 of which a Note for $710,394 was issued
to the Holder (the "Note").  In the event of the repayment of any portion of the
principal amount of the Note by the Company (a "Repayment"), the number of
Warrant Shares covered by this Warrant shall be reduced, effective concurrently
with the Repayment, to a number determined by multiplying the number of Warrant
Shares covered by this Warrant immediately prior to the Repayment by a fraction,
the numerator of which shall be the principal amount of the Notes outstanding
immediately following the Repayment and the denominator of which shall be the
principal amount of the Notes outstanding immediately prior to the Repayment.
In the event of a Repayment of the entire principal amount of the Note, this
Warrant shall be cancelled immediately upon such Repayment.  Notwithstanding
anything above, in the event the Repayment is a prepayment pursuant to Section
6.2 of the Securities Purchase Agreement, the notice provided for in Section 6.3
of the Securities Purchase Agreement shall apply, and during such notice period,
the Holder shall be entitled to exercise this Warrant in accordance with the
terms hereof.

Section 10. Notices.  In the event that:
            -------

            (A)   the Company proposes to pay any dividend payable in stock (of
     any class or classes) or any obligations or stock convertible into or
     exchangeable for shares of Ordinary Shares upon its Ordinary Shares or make
     any distribution (other than ordinary cash dividends) to the holders of its
     Ordinary Shares;

            (B)   the Company proposes to grant to the holders of its Ordinary
     Shares generally any rights or warrants (excluding any warrants granted to
     any employee, director, officer, contractor or consultant of the Company
     pursuant to any plan approved by the Board of Directors of the Company);

            (C)   the Company proposes to effect any capital reorganization or
     reclassification of capital stock of the Company;

            (D)   the Company proposes to consolidate with, or merge into, any
     other Company or to transfer its property as an entirety or substantially
     as an entirety; or

            (E)   the Company proposes to effect the liquidation, dissolution or
     winding up of the Company,

then the Company shall cause notice of any such intended action to be given to
the Holder of this Warrant not less than 30 days before the date on which the
transfer books of the Company shall

                                       12
<PAGE>

close or a record shall be taken for such stock dividend, distribution or
granting of rights or Warrants, or the date when such capital reorganization,
reclassification, consolidation, merger, transfer, liquidation, dissolution or
winding up shall be effective, as the case may be.

     Any notice or other document required or permitted to be given or delivered
to the Holder of this Warrant shall be delivered in accordance with Section 15
herein.

Section 11.  Limitation of Liability; Not Shareholders.  No provision of this
             -----------------------------------------
Warrant shall be construed as conferring upon the Holder the right to vote or to
consent or to receive dividends or to receive notice as a shareholder in respect
of meetings of shareholders for the election of directors of the Company or any
other matter whatsoever as shareholders of the Company.  No provision hereof, in
the absence of affirmative action by the Holder to purchase shares of Ordinary
Shares, and no mere enumeration herein of the rights or privileges of the
Holder, shall give rise to any liability of Holder for the purchase price or as
a shareholder of the Company, whether such liability is asserted by the Company,
creditors of the Company or others.

Section 12.  Loss, Destruction of Warrant.  Upon receipt of evidence
             ----------------------------
satisfactory to the Company of the loss, theft, mutilation or destruction of
this Warrant, and in the case of any such loss, theft or destruction upon
delivery of a bond of indemnity in such form and amount as shall be reasonably
satisfactory to the Company (the original Warrantholder's indemnity being
satisfactory indemnity in the event of loss, theft or destruction of any Warrant
owned by such holder), or in the event of such mutilation upon surrender and
cancellation of this Warrant, the Company will make and deliver a new Warrant,
of like tenor and representing the right to purchase the same Aggregate Number
of Ordinary Shares, as adjusted in Section 5, as provided for in such lost,
stolen, destroyed or mutilated Warrant, in lieu of such lost, stolen, destroyed
or mutilated Warrant.  Any Warrant issued under the provisions of this Section
12 in lieu of any Warrant alleged to be lost, destroyed or stolen, or of any
mutilated Warrant, shall constitute an original contractual obligation on the
part of the Company.

Section 13.  Amendments.  Neither this Warrant nor any term hereof may be
             ----------
changed, waived, discharged or terminated orally or in writing, provided that
any term of this Warrant may be amended or the observance of such term may be
waived (either generally or in a particular instance and either retroactively or
prospectively) with, but only with, the written consent of the Company and the
Holders of the Warrants that are exercisable for a number of Ordinary Shares
that represent in the aggregate at least a majority of the total number of
Ordinary Shares for which all of the Warrants are then exercisable (whether or
not the Holder of this Warrant consents).

Section 14.  Severability.  If in any jurisdiction, any provision of this
             ------------
Agreement or its application to any party or circumstance is restricted,
prohibited or unenforceable, such provision shall, as to such jurisdiction, be
ineffective only to the extent of such restriction, prohibition or
unenforceability without invalidating the remaining provisions hereof and
without affecting the validity or enforceability of such provision in any other
jurisdiction or its application to other parties or circumstances.

                                       13
<PAGE>

Section 15.    Notice.  Any notice or document required or permitted by this
               ------
Agreement to be given to a party hereto shall be in writing and is sufficiently
given if delivered personally, or if sent by prepaid certified mail, return
receipt requested, to such party addressed as follows:

     (i)       If to the Company:  Senetek Plc
                                   620 Airpark Road
                                   Napa, California  94558
                                   Attention: President

               copy to:            Latham & Watkins
                                   505 Montgomery Street, Suite 1900
                                   San Francisco, California  94111
                                   Attention:  Jeffrey T. Pero, Esq.

     (v)       If to the Holder:   c/o Robert T. Tucker, Esq.
                                   61 Purchase Street, Suite 2
                                   Rye, New York  10580

               copy to:            Pryor Cashman Sherman & Flynn LLP
                                   410 Park Avenue
                                   New York, New York  10022
                                   Attention: Selig D. Sacks, Esq.

Notice so mailed shall be deemed to have been given upon receipt if delivered
personally or on the fifth business day next following the date of the returned
receipt.  Any notice delivered to the party to whom it is addressed shall be
deemed to have been given and received on the day it is delivered.  Any party
may from time to time notify the others in the manner provided herein of any
change of address which thereafter, until changed by like notice, shall be the
address of such party for all purposes hereof.

Section 16.    Governing Law; Choice Of Forum; Certain Consents; Waiver Of Jury
               ----------------------------------------------------------------
               Trial, Counterclaim, Setoff.
               ----------------------------

     THIS WARRANT SHALL BE DEEMED TO HAVE BEEN EXECUTED AND DELIVERED AT AND
SHALL BE DEEMED TO HAVE BEEN MADE IN NEW YORK, NEW YORK.  THIS WARRANT, AND THE
RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE
WITH AND BE GOVERNED BY THE SUBSTANTIVE LAWS OF THE STATE OF NEW YORK (WITHOUT
GIVING EFFECT TO ANY OF SUCH STATE'S CONFLICT OF LAWS RULES OR PRINCIPLES).  ANY
LEGAL ACTION OR PROCEEDING WITH RESPECT HERETO AND THERETO SHALL ONLY BE BROUGHT
IN ANY STATE OR FEDERAL COURT IN THE BOROUGH OF MANHATTAN, NEW YORK CITY, NEW
YORK, AND, BY EXECUTION, ACCEPTANCE AND DELIVERY OF THIS WARRANT, THE COMPANY
HEREBY IRREVOCABLY ACCEPTS FOR ITSELF AND IN RESPECT OF ITS PROPERTY, GENERALLY
AND UNCONDITIONALLY, THE JURISDICTION OF THE AFORESAID COURTS AND

                                       14
<PAGE>

IRREVOCABLY WAIVES ANY OBJECTION, DEFENSE OR CLAIM TO SUCH JURISDICTION WHICH
MAY BE BASED, DIRECTLY OR INDIRECTLY, ON THE GROUNDS OF FORUM NON CONVENIENS
THAT IT MAY NOW OR HEREAFTER HAVE TO THE BRINGING OF ANY ACTION OR PROCEEDING IN
SUCH JURISDICTION IN RESPECT OF THIS WARRANT. IF ANY ACTION IS COMMENCED IN ANY
OTHER JURISDICTION, THE PARTIES HERETO HEREBY CONSENT TO THE REMOVAL OF SUCH
ACTION TO THE AFOREMENTIONED COURTS. THE COMPANY FURTHER IRREVOCABLY CONSENTS TO
THE SERVICE OF PROCESS OUT OF ANY OF THE AFOREMENTIONED COURTS IN ANY SUCH
ACTION OR PROCEEDING BY THE MAILING OF COPIES THEREOF BY REGISTERED OR CERTIFIED
MAIL, POSTAGE PREPAID, TO THE COMPANY AT ITS ADDRESS, SUCH SERVICE TO BECOME
EFFECTIVE 30 DAYS AFTER SUCH MAILING. NOTHING HEREIN SHALL AFFECT THE RIGHT OF
THE HOLDERS OF ANY OF THE WARRANTS OR WARRANT SHARES TO SERVE PROCESS IN ANY
OTHER MANNER PERMITTED BY LAW OR COMMENCE LEGAL PROCEEDINGS OR OTHERWISE PROCEED
AGAINST THE COMPANY IN ANY OTHER JURISDICTION. THE COMPANY WAIVES IN EACH SUCH
ACTION AND OTHER LEGAL PROCEEDING THE RIGHT TO TRIAL BY JURY AND THE RIGHT TO
ASSERT ANY COUNTERCLAIM OR SETOFF.

     [signature page follows; remainder of page left intentionally blank]

                                       15
<PAGE>

     IN WITNESS WHEREOF, the Company has caused this Amended and Restated
Warrant to be signed in its name by its duly authorized officer.

Dated:  ____________, 2001

                         SENETEK PLC

                         By:___________________________
                            Name:
                            Title:

                                       16
<PAGE>

                                                                       Exhibit 1

                                EXERCISE NOTICE

     The undersigned Holder hereby elects to exercise purchase rights
represented by such Warrant for, and to purchase thereunder ________ Ordinary
Shares covered by such Warrant and herewith makes payment in full therefor of
$_________ cash and/or by cancellation of $__________ of indebtedness of the
Company to the Holder hereof and requests that, subject to the terms and
conditions of the Warrant, certificates for such shares (and any securities or
property deliverable upon such exercise) be issued in the name of and delivered
to ______________________ whose address is ___________________________________,
and whose social security or employer identification number is ____________.

     The undersigned agrees that, in the absence of an effective registration
statement with respect to Ordinary Shares issued upon this exercise, the
undersigned is acquiring such Ordinary Shares for the Holder's own account and
not as a nominee for any other party, for investment and not with a view to
distribution thereof and that the certificate or certificates representing such
Ordinary Shares may bear a legend substantially as follows:

     THESE SHARES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
     AMENDED, AND MAY NOT BE OFFERED, SOLD, TRANSFERRED, ASSIGNED OR
     HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH
     RESPECT TO SUCH SECURITIES UNDER THE ACT AND APPLICABLE STATE SECURITIES
     LAW OR AN OPINION OF COUNSEL REASONABLY  SATISFACTORY TO THE COMPANY THAT
     SUCH REGISTRATION IS NOT REQUIRED.

     In addition, the undersigned agrees that, in the absence of an effective
registration statement with respect to Ordinary Shares issued upon this
exercise, stop transfer instructions will be entered on the Company's stock
transfer records with respect to Ordinary Shares issued upon this exercise.

Dated:                        __________________________
                              Signature guaranteed:

<PAGE>

                              FORM OF ASSIGNMENT

     FOR VALUE RECEIVED the undersigned registered Holder of the within Warrant
hereby sells, assigns, and transfers unto the Assignee(s) named below (including
the undersigned with respect to any Warrants constituting a part of the Warrants
evidenced by the within Warrant not being assigned hereby) all of the right of
the undersigned under the within Warrant, with respect to the number of Warrants
set forth below:

<TABLE>
<CAPTION>
                                             Social security or
                                              other identifying
    Name of Assignees       Address         number of Assignee(s)     Number of Warrants
    -----------------       -------         ---------------------     ------------------
<S>                        <C>                    <C>                      <C>

</TABLE>

and does hereby irrevocably constitute and appoint ______________ the
undersigned's attorney to make such transfer on the books of _____________
maintained for that purpose, with full power of substitution in the premises.

Dated: ______________

                              _________________________________(1)
                              (Signature of Owner)

                              _________________________________
                              (Street Address)

                              _________________________________
                              (City)  (State)  (Zip Code)

-----------------

(1)  The signature must correspond with the name as written upon the face of the
     within Warrant in every particular, without alteration or enlargement or
     any change whatsoever.

                                       18<PAGE>

                                                                    Exhibit 10.6

                                                                  EXECUTION COPY

                             AMENDED AND RESTATED
                         REGISTRATION RIGHTS AGREEMENT
                         -----------------------------

     AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT, dated as of June 20,
2001, among SENETEK, P.L.C., a corporation organized under the laws of England
(the "Company"), SILVER CREEK INVESTMENTS, LTD., a British Virgin Islands
company ("Silver Creek"), BOMOSEEN INVESTMENTS, LTD., a British Virgin Islands
company ("Bomoseen"), ELSTREE HOLDINGS, LTD., a British Virgin Islands company
("Elstree"), DANDELION INVESTMENTS, LTD., a British Virgin Islands company
("Dandelion"), SCORPION HOLDINGS INC., a Delaware company ("Scorpion Holdings"),
and WALLINGTON INVESTMENTS LIMITED, a British Virgin Islands company
("Wallington").

                                  WITNESSETH:

          WHEREAS, on April 14, 1999, Silver Creek, Bomoseen, Elstree and
Dandelion were issued (i) Senior Notes due 2002 in an aggregate principal amount
of $7,388,570 (collectively, the "Notes") and (ii) Warrants (as defined herein)
by the Company;

          WHEREAS, as a condition to the issuance of the Warrants to Silver
Creek, Bomoseen, Elstree and Dandelion, the Company agreed to provide certain
registration rights pursuant to the terms of this Agreement;

          WHEREAS, as of the date hereof, Wallington has agreed to extend
certain financial accommodations to the Company in connection with the financing
of the working capital needs of the Company pursuant to the terms of a certain
Revolving Credit Agreement between the Company and Wallington dated as of the
date hereof (the "Credit Agreement");

          WHEREAS, as of the date hereof, as a condition to Wallington entering
into the Credit Agreement, the Company, Silver Creek, Bomoseen, Elstree and
Dandelion have amended the Securities Purchase Agreement pursuant to a First
Amendment to Securities Purchase Agreement dated as of the date hereof (the
"First Amendment") in order to, among other things, permit the Company to enter
into the Credit Agreement and amend and restate the Notes and Warrants;

          WHEREAS, concurrently herewith, the Company and Scorpion Holdings
shall execute the Investment Advice Agreement dated as of the date hereof (the
"Advice Agreement"), in connection with investment advice provided to the
Company by Scorpion Holdings;

          WHEREAS, in connection with the Advice Agreement and the Credit
Agreement, Scorpion Holdings and Wallington shall, subject to certain terms and
conditions, be issued Ordinary Shares (as defined herein); and

                                       1
<PAGE>

          WHEREAS, the parties hereto desire to amend and restate this Agreement
in order to add Scorpion Holdings and Wallington as parties to this Agreement
and to set forth the registration rights of such parties and the obligations of
the Company with respect thereto;

          NOW, THEREFORE, in consideration of the mutual covenants and
obligations hereinafter set forth, the parties hereto, intending to be legally
bound, hereby agree as follows:

     1.   Definitions. For purposes of this Agreement, capitalized terms used
          -----------
herein shall have the meanings set forth in the preambles hereto and in this
Section 1.

          1.1  "Commission" shall mean the Securities and Exchange Commission or
any other federal agency at the time administering the Securities Act.

          1.2  "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended, or any similar federal statute enacted hereafter, and the rules and
regulations of the Commission thereunder, all as the same shall be in effect
from time to time.

          1.3  "Fee Shares" shall mean the number of Ordinary Shares issued or
issuable to Scorpion Holdings (i) pursuant to Sections 2 and 3 of the Advice
Agreement and (ii) pursuant to Section 2.6 of the Credit Agreement.

          1.4  "Form S-3" means such form under the Securities Act as in effect
on the date hereof or any registration form under the Securities Act
subsequently adopted by the Commission which permits inclusion or incorporation
of substantial information by reference to other documents filed by the Company
with the Commission.

          1.5  "Holder" shall mean any holder of Registrable Securities;
provided, however, that any Person who acquires any of the Registrable
-----------------
Securities in a distribution pursuant to a registration statement filed by the
Company under the Securities Act or pursuant to a sale under Rule 144 under the
Securities Act shall not be considered a Holder.

          1.6  "Initiating Holders" shall mean Holders representing (on a fully
diluted basis) at least twenty percent (20%) of the total number of Registrable
Securities.

          1.7  "Ordinary Shares" shall mean the ordinary shares, par value (5p)
per share, of the Company which may be represented by American Depository
Receipts, or, in the case of a conversion, reclassification or exchange of such
Ordinary Shares, shares of the stock into or for which such Ordinary Shares
shall be converted, reclassified or exchanged, and all provisions of this
Agreement shall be applied appropriately thereto and to any stock resulting from
any subsequent conversion, reclassification or exchange therefor.

                                       2
<PAGE>

          1.8  "Person" shall mean any individual, firm, corporation,
partnership, trust, incorporated or unincorporated association, joint venture,
joint stock company, government (or an agency or political subdivision thereof)
or other entity of any kind.

          1.9  "Register", "registered" and "registration" shall refer to a
registration effected by preparing and filing a registration statement with the
Commission in compliance with the Securities Act and applicable rules and
regulations thereunder, and the declaration or ordering of the effectiveness of
such registration statement by the Commission.

          1.10 "Registrable Securities" shall mean (i) the Warrant Shares, (ii)
the Fee Shares, (iii) the Ordinary Shares issued upon conversion of any loan
amounts (including, without limitation, interest) into Ordinary Shares pursuant
to Section 2.6 of the Credit Agreement, and (iv) all Ordinary Shares now owned
or issued on the date hereof to the Holders or hereafter issued by the Company
to the Holders pursuant to a commitment existing on the date hereof; provided,
                                                                     --------
however, that the Ordinary Shares shall only be treated as Registrable
-------
Securities hereunder if and so long as they have not been sold pursuant to a
registration statement under the Securities Act or those shares shall not have
been sold pursuant to Rule 144 under the Securities Act or any similar or
successor rule; and provided, further, that the Company shall not be required to
                    --------  -------
register Warrants. Registrable Securities shall not include any of the foregoing
securities held by any Holder who is not an affiliate of the Company within the
meaning of Rule 144 under the Securities Act and that may be sold pursuant to
Rule 144(k) under the Securities Act.

          1.11 "Registration Expenses" shall mean all expenses incurred by the
Company in compliance herewith, including, without limitation, all registration
and filing fees, printing expenses, fees and disbursements of counsel for the
Company, and, in connection with a registration pursuant to Section 2 hereof,
the reasonable fees and expenses (subject to documentation thereof) of one
counsel for all Holders, blue sky fees and expenses, and the expense of any
special audits incident to or required by any such registration (but excluding
the compensation of regular employees of the Company, which shall be paid in any
event by the Company).

          1.12 "Securities Act" shall mean the Securities Act of 1933, as
amended, or any similar federal statute enacted hereafter, and the rules and
regulations of the Commission thereunder, all as the same shall be in effect
from time to time.

          1.13 "Securities Purchase Agreement" shall mean that certain
Securities Purchase Agreement dated as of April 14, 1999, as amended from time
to time, among the Company, Silver Creek, Bomoseen, Elstree and Dandelion.

          1.14 "Selling Expenses" shall mean all underwriting discounts and
commissions applicable to the sale of Registrable Securities.

          1.15 "Warrants" shall mean all the warrants issued pursuant to the
Securities Purchase Agreement.

                                       3
<PAGE>

          1.16 "Warrant Shares" shall mean the Ordinary Shares issued or
issuable upon exercise of the Warrants, as such number of shares may be adjusted
in accordance with the terms of the Warrants.

     2.   Requested Registration.
          ----------------------

          2.1  Request for Registration. At any time from and after the date
               ------------------------
hereof if the Company shall receive from Initiating Holders a written request
that the Company effect a registration with respect to Registrable Securities
the Company will:

               (a)  promptly give written notice of the proposed registration to
all other Holders; and

               (b)  as soon as practicable, use its best efforts to effect such
registration (including, without limitation, the execution of an undertaking to
file post-effective amendments, appropriate qualification under the blue sky or
other state securities laws requested by Initiating Holders and appropriate
compliance with applicable regulations issued under the Securities Act) as may
be so requested and as would permit or facilitate the sale and distribution of
all or such portion of such Registrable Securities as are specified in such
request, together with all or such portion of the Registrable Securities of any
Holder or Holders joining in such request as are specified in a written request
given within twenty-one (21) days after receipt of such written notice from the
Company; provided, that the Company shall not be obligated to effect, or to take
         --------
any action to effect, any such registration pursuant to this Section 2 after the
first such registration pursuant to this Section 2.1 has been declared or
ordered effective.

          2.2  Additional Shares to be Included. The registration statement
               --------------------------------
filed pursuant to the request of the Initiating Holders may, subject to the
provisions of Section 2.4 below, include (a) other securities of the Company
(the "Additional Shares") which are held by (i) officers or directors of the
Company who, by virtue of agreements with the Company, are entitled to include
their securities in any such registration or (ii) other persons who, by virtue
of agreements with the Company, are entitled to include their securities in any
such registration (the "Other Stockholders"), and (b) securities of the Company
being sold for the account of the Company.

          2.3  Underwriting.
               -------------

               (a)  If the Initiating Holders intend to distribute the
Registrable Securities covered by their request by means of an underwriting,
they shall so advise the Company as a part of their request made pursuant to
this Section 2 and the Company shall include such information in the written
notice to other Holders referred to in Section 2.1 above. The right of any
Holder to registration pursuant to this Section 2 shall be conditioned upon such
Holder's participation in such underwriting and the inclusion of such Holder's
Registrable Securities in the underwriting to the extent provided herein and
subject to the limitations provided herein. A Holder may elect to include in
such underwriting all or a part of the Registrable Securities he holds.

                                       4
<PAGE>

               (b)  The Company shall (together with all Holders, officers,
directors and Other Stockholders proposing to distribute their securities
through such underwriting) negotiate and enter into an underwriting agreement in
customary form with the representative of the underwriter or underwriters
selected for such underwriting by a majority in interest of the Initiating
Holders, which underwriter(s) shall be reasonably acceptable to the Company.

          2.4  Limitations on Shares to be Included. Notwithstanding any other
               ------------------------------------
provision of this Section 2, if the representative of the underwriters advises
the Initiating Holders in writing that marketing factors require a limitation on
the number of shares to be underwritten in the registration requested pursuant
to Section 2.1 hereof, first the Additional Shares shall be excluded from such
                       ------
registration to the extent so required by such limitation, second securities
                                                           -------
being sold for the account of the Company shall be excluded from such
registration and, thereafter, if a limitation on the number of shares is still
                  ----------
required, the number of shares that may be included in the registration and
underwriting shall be allocated among all Holders, including Initiating Holders,
in proportion, as nearly practicable, to the respective amounts of Registrable
Securities which they have requested to be included in such registration
statement. If the Company or any Holder, officer, director or Other Stockholder
who has requested inclusion in such registration as provided above disapproves
of the terms of any such underwriting, such person may elect to withdraw such
person's Registrable Securities or Additional Shares therefrom by written notice
to the Company and the underwriter and the Initiating Holders. Any Registrable
Securities or other securities excluded shall also be withdrawn from such
registration. No Registrable Securities or Additional Shares excluded from such
registration by reason of such underwriters' marketing limitation shall be
included in such registration. To facilitate the allocation of shares in
accordance with this Section 2.4, the Company or underwriter or underwriters
selected as provided above may round the number of Registrable Securities of any
Holder which may be included in such registration to the nearest 100 shares.

     3.   Company Registration.
          ---------------------

          3.1  Piggy-Back Rights. If the Company shall determine to register
               -----------------
under the Securities Act any of its equity securities or securities convertible
into equity securities either for its own account or the account of a security
holder or holders exercising any demand registration rights, other than a
registration relating solely to employee benefit plans, or a registration
relating solely to a Commission Rule 145 transaction, or a registration on Form
S-4 or S-8 (or any successor forms thereto), the Company will:

               (a)  promptly give to each Holder written notice thereof (which
shall include a list of the jurisdictions in which the Company intends to
attempt to qualify such securities under the applicable blue sky or other state
securities laws); and

               (b)  include in such registration (and, subject to Section
6.3(a), any related qualification under blue sky laws), and in any underwriting
involved therein, all the Registrable Securities specified in a written request
or request, made by any Holder within twenty-one (21) days after receipt of the
written notice from the Company described in clause (a) above, except as set
forth in Section 3.3 below. Such written request may specify all or a part of a
Holder's Registrable Securities.

                                       5
<PAGE>

          3.2  Underwriting. If the registration of which the Company gives
               ------------
notice is for a registered public offering involving an underwriting, the
Company shall so advise the Holders as a part of the written notice given
pursuant to Section 3.1(a). The right of any Holder to registration pursuant to
this Section 3 shall be conditioned upon such Holder's participation in such
underwriting and the inclusion of such Holder's Registrable Securities in the
underwriting to the extent provided herein. All Holders proposing to distribute
their securities through such underwriting shall (together with the Company and
any officers, directors or Other Stockholders distributing their securities
through such underwriting) enter into an underwriting agreement in customary
form with the representative of the underwriter or underwriters selected by the
Company.

          3.3  Limitations on Shares to be Included. Notwithstanding any other
               ------------------------------------
provision of this Section 3, if the representative of the underwriters advises
the Company in writing that marketing factors require a limitation or
elimination on the number of shares to be underwritten, the Company may (subject
to the allocation priority set forth below) limit the number of or eliminate the
Registrable Securities to be included in the registration and underwriting. The
Company shall so advise all holders of securities requesting registration, and
the number of shares of securities that are entitled to be included in the
registration and underwriting shall be allocated as follows: first, to the
                                                             -----
Company for securities being sold for its own account; second, the Registrable
                                                       ------
Securities which have been requested to be included by the Holders, pro rata
based upon the aggregate number of Registrable Securities held by the respective
Holders; and thereafter, the number of shares that may be included in the
             ----------
registration statement and underwriting shall be allocated among all officers,
directors or Other Stockholders in each case in proportion, as nearly as
practicable, to the respective amounts of Additional Shares which they had
requested to be included in such registration at the time of filing the
registration statement. If any Holder of Registrable Securities or any officer,
director or Other Stockholder disapproves of the terms of any such underwriting,
he may elect to withdraw therefrom by written notice to the Company and the
underwriter. Any Registrable Securities or other securities excluded or
withdrawn from such underwriting shall also be withdrawn from such registration.
The Company shall have the right to terminate or withdraw any registration
initiated by it under this Section 3 prior to the effectiveness of such
registration whether or not any Holder has elected to include securities in such
registration.

     4.   Registration on Form S-3. In addition to their rights set forth in
          ------------------------
Sections 2 and 3 above, if at any time (i) Initiating Holders request that the
Company file a registration statement on Form S-3 (or any successor form
thereto) for a public offering of all or any portion of the Registrable
Securities held by such Initiating Holder or Holders (such request shall be in
writing and shall state the number of Registrable Securities to be disposed of
and, to the extent practicable, the intended methods of disposition of the
Registrable Securities by such Initiating Holder or Holders), and (ii) the
Company is a registrant entitled to use Form S-3 (or any successor form thereto)
to register such securities, then the Company shall use its best efforts to
register (including by means of a shelf registration pursuant to Rule 415 under
the Securities Act if so requested in such request) under the Securities Act on
Form S-3 (or any successor form thereto), 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. Registrations effected

                                       6
<PAGE>

pursuant to this Section 4 shall not be counted as demands for registration or
registrations effected pursuant to Section 2 or 3, respectively.

     5.   Expenses of Registration. All Registration Expenses incurred in
          ------------------------
connection with any registration, qualification or compliance pursuant to
Sections 2, 3 or 4 of this Agreement shall be borne by the Company. Selling
Expenses shall be borne pro rata by each Holder in accordance with the number of
shares sold.

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

          6.1  Procedure. In the case of each registration effected by the
               ---------
Company pursuant to this Agreement, the Company will keep each Holder advised in
writing as to the initiation of each registration and as to the completion
thereof and will, at its expense:

               (a)  use its best efforts to keep such registration effective for
a period of 180 days or until the Holder or Holders have completed the
distribution described in the registration statement relating thereto, whichever
first occurs; and provided, that in the case of any registration of Registrable
Securities on Form S-3 which are intended to be offered on a continuous or
delayed basis, such 180-day period shall, at the cost and expense of the
Company, be extended, if necessary, to keep the registration statement effective
until all such Registrable Securities are sold, provided that Rule 415, or any
successor rule under the Securities Act, permits an offering on a continuous or
delayed basis, and provided, further, that applicable rules and regulations
                   -----------------
under the Securities Act governing the obligation to file a post-effective
amendment permit, in lieu of filing a post-effective amendment which (y)
includes any prospectus required by Section 10(a)(3) of the Securities Act or
(z) reflects facts or events representing a material or fundamental change in
the information set forth in the registration statement, the incorporation by
reference of information otherwise required to be included in such post-
effective amendment covered by (y) and (z) above to be contained in periodic
reports filed pursuant to Section 13 or 15(d) of the Exchange Act in the
registration statement;

               (b)  Subject to the limitations set forth in Section 6.1 (a)
hereof, prepare and file with the Commission such amendments and supplements to
such registration statement and the prospectus used in connection with such
registration statement as may be necessary to comply with the provisions of the
Securities Act with respect to the disposition of all securities covered by such
registration statement;

               (c)  Furnish such number of prospectuses and other documents
incident thereto, including any amendment of or supplement to the prospectus, as
a Holder from time to time may reasonably request;

               (d)  Notify each seller of Registrable Securities covered by such
registration statement at any time when a prospectus relating thereto 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, as
then in effect, includes an untrue statement of a material fact or omits to
state a material fact required to be stated therein or necessary to make the
statements therein not misleading or incomplete in the light of the
circumstances then

                                       7
<PAGE>

existing (in which case each person entitled to sell under such registration
statement will immediately suspend use of such registration statement until it
is supplemented or amended as provided herein), and at the request of any such
seller, prepare and furnish to such seller a reasonable number of copies of a
supplement to or an amendment of such prospectus as may be necessary so that, as
thereafter delivered to the purchasers of such shares, such prospectus shall not
include an untrue statement of a material fact or omit to state a material fact
required to be stated therein or necessary to make the statements therein not
misleading or incomplete in the light of the circumstances then existing;

               (e)  List all such Registrable Securities registered in such
registration on each securities exchange or automated quotation system on which
the Ordinary Shares of the Company are then listed;

               (f)  Provide a transfer agent and registrar for all Registrable
Securities and a CUSIP number for all such Registrable Securities, in each case
not later than the effective date of such registration;

               (g)  The Company will give the Holders on whose behalf such
Registrable Securities are to be registered and their underwriters, if any, and
their respective counsel and accountants, the opportunity to review such
registration statement, each prospectus included therein or filed with the
Commission, and each amendment thereof or supplement thereto, and will give each
such Holder such access to the Company's books, financial and other records,
pertinent corporate documents and such opportunities to discuss the business of
the Company with its officers, its counsel and the independent public
accountants who have certified the Company's financial statements, as shall be
necessary, in the opinion of such Holders or such underwriters or their
respective counsel, in order to conduct a reasonable and diligent investigation
within the meaning of the Securities Act, provided that such seller,
underwriter, attorney or accountant shall agree to hold in confidence and trust
all information so provided;

               (h)  Furnish to each selling Holder upon request a signed
counterpart. addressed to each such selling Holder, of

                    (i)  an opinion of counsel for the Company, dated the
effective date of the registration statement in form reasonably acceptable to
the Company and such counsel, and

                    (ii) "comfort" letters signed by the Company's independent
public accountants who have examined and reported on the Company's financial
statements included in the registration statement, to the extent permitted by
the standards of the American Institute of Certified Public Accountants or other
relevant authorities, covering such matters as are customarily covered in
opinions of issuer's counsel and accountants' "comfort" letters delivered to
underwriters in underwritten public offerings of securities;

               (i)  Furnish to each selling Holder upon request a copy of all
documents filed with and all correspondence from or to the Commission in
connection with any such offering; and

                                       8
<PAGE>

               (j)  Make available to its security holders, as soon as
reasonably practicable, an earnings statement covering the period of at least
twelve months, but not more than eighteen months, beginning with the first month
after the effective date of the Registration Statement, which earnings statement
shall satisfy the provisions of Section 11 (a) of the Securities Act.

          6.2  Holder Information. It shall be a condition precedent to the
               ------------------
obligations of the Company to take any action pursuant to this Agreement that
the Holders proposing to register Registrable Securities shall furnish to the
Company such information regarding themselves, the Registrable Securities held
by them, and their intended method of distribution of such Registrable
Securities as the Company shall reasonably request and as shall be required in
connection with the action to be taken by the Company.

          6.3  Limitations on Obligations of the Company. Notwithstanding any
               -----------------------------------------
other provision in this Agreement to the contrary, the Company shall not be
obligated to take any action:

               (a)  pursuant to Sections 2, 3 or 4 of this Agreement (A) in any
particular jurisdiction in which the Company would be required to execute a
general consent to service of process unless the Company is already subject to
service in such jurisdiction, (B) in any non-U.S. jurisdiction in which the
Company would be required to qualify as a foreign corporation eligible to do
business in such jurisdiction, if the Company shall not then be so qualified in
that jurisdiction or (C) in any non-U.S. jurisdiction that would subject the
Company to taxation where it would not otherwise be subject to tax;

               (b)  pursuant to Section 2 or 4 of this Agreement if the Company,
within ten (10) days of the receipt of the request of the Initiating Holders,
gives notice of its bona fide intention to file a registration statement with
the Commission within sixty (60) days of receipt of such request (other than a
registration statement on Form S-8);

               (c)  pursuant to Section 2 or 4 of this Agreement with respect to
any request for registration made by Initiating Holders during the period
starting with the date of filing of, and ending on the date ninety (90) days
immediately following the effective date of, any registration statement
pertaining to equity securities of the Company (other than a registration
statement on Form S-8);

               (d)  pursuant to Section 2 or 4 of this Agreement if the Company
shall furnish to Holders requesting registration a certificate signed by the
President or Chief Executive Officer of the Company (the "Certificate") stating
that the negotiation or consummation of a transaction by the Company is pending
or an event has occurred, which negotiation, consummation or event would require
additional disclosure by the Company in the registration statement of material
information which the Company (in the good faith judgment of its Board of
Directors) has a bona fide business purpose for keeping confidential and the
nondisclosure of which in the registration statement would cause the
registration statement to fail to comply with applicable disclosure
requirements, in which case the Company's obligation hereunder to file a

                                       9
<PAGE>

registration statement, pursue its effectiveness or maintain its effectiveness,
shall be deferred for a period or periods not to exceed one hundred and eighty
(180) consecutive days in any 12month period; and the Company may suspend after
providing a Certificate the use of any effective registration statement filed
pursuant to Section 2, 3 or 4 of this Agreement during any period the Company's
obligation to file a registration statement or to pursue or maintain its
effectiveness would be deferred as provided herein; or

               (e)  pursuant to Section 2 or 4 of this Agreement if the Holder
requires an audit of the Company's financial statements in connection with the
registration of the Registrable Securities other than any audit required by the
Securities Act or any rules or regulations thereunder.

     7.   Indemnification.
          ---------------

          7.1  Indemnification by the Company. The Company will indemnify each
               ------------------------------
Holder, each of its officers, directors and partners, and each person
controlling such Holder, with respect to which registration, qualification or
compliance has been effected pursuant to this Agreement, and each underwriter,
if any, and each person who controls any underwriter, against all claims,
losses, damages and liabilities (or actions, proceedings or settlements in
respect thereof) arising out of or based on any untrue statement (or alleged
untrue statement) of a material fact contained in any prospectus, offering
circular or other document (including any related registration statement,
notification or the like) incident to any such registration, qualification or
compliance, or based on any omission (or alleged omission) to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, and will reimburse each such Holder, each of its
officers, directors and partners, and each person controlling such Holder, each
such underwriter and each person who controls any such underwriter, for any
legal and any other expenses reasonably incurred in connection with
investigating and defending or settling any such claim, loss, damage, liability
or action, provided that the Company will not be liable in any such case to the
extent that any such claim, loss, damage, liability or expense arises out of or
is based on any untrue statement or omission (or alleged untrue statement or
omission) made in reliance upon and based upon written information furnished to
the Company by such Holder or underwriter and stated to be specifically for use
therein.

          7.2  Indemnification by the Holders. Each Holder will, if Registrable
               ------------------------------
Securities held by him are included in the securities as to which such
registration, qualification or compliance is being effected, indemnify the
Company, each of its directors and officers and each underwriter, if any, of the
Company's securities covered by such a registration statement, each person who
controls the Company (other than such Holder) or such underwriter within the
meaning of the Securities Act and the rules and regulations thereunder, each
other such Holder and each of their officers, directors and partners, and each
person controlling such Holder or other stockholder, against all claims, losses,
damages, expenses and liabilities (or actions in respect thereof) arising out of
or based on any untrue statement (or alleged untrue statement) of a material
fact contained in any such registration statement, prospectus, offering circular
or other document, or any omission (or alleged omission) to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, and will reimburse the

                                       10
<PAGE>

Company, each of its directors and officers, each underwriter and control
person, each other Holder and each of their officers, directors and partners and
each person controlling such Holder or other stockholder for any legal or any
other expenses reasonably incurred in connection with investigating or defending
any such claim, loss, damage, liability or action, in each case to the extent,
but only to the extent, that such untrue statement (or alleged untrue statement)
or omission (or alleged omission) is made in such registration statement,
prospectus, offering circular or other document in reliance upon and in
conformity with written information furnished to the Company by such Holder and
stated to be specifically for use therein.

          7.3  Notices of Claims, Procedures, etc. Each party entitled to
               ------------------------------------
indemnification under this Section 7 (the "Indemnified Party") shall give notice
to the party required to provide indemnification (the "Indemnifying Party")
promptly after such Indemnified Party has actual knowledge of any claim as to
which indemnity may be sought, and shall permit the Indemnifying Party to assume
the defense of any such claim or any litigation resulting therefrom, provided
that counsel for the Indemnifying Party, who shall conduct the defense of such
claim or any litigation resulting therefrom, shall be approved by the
Indemnified Party (whose approval shall not be unreasonably withheld), and the
Indemnified Party may participate in such defense at the Indemnified Party's
sole expense, and provided further that the failure of any Indemnified Party to
give notice as provided herein shall not relieve the Indemnifying Party of its
obligations under this Section 7 unless such failure is prejudicial to the
ability of Indemnifying Party to defend such claim or action. Notwithstanding
the foregoing, such Indemnified Party shall have the right to employ its own
counsel in any such litigation, proceeding or other action if (i) the employment
of such counsel has been authorized by the Indemnifying Party, in its sole and
absolute discretion, or (ii) the named parties in any such claims (including any
impleaded parties) include any such Indemnified Party and the Indemnified Party
and the Indemnifying Party shall have been advised in writing (in suitable
detail) by counsel to the Indemnified Party either (A) that there may be one or
more legal defenses available to such Indemnified Party which are different from
or additional to those available to the Indemnifying Party, or (B) that there is
a conflict of interest by virtue of the Indemnified Party and the Indemnifying
Parties having common counsel, in any of which events, the legal fees and
expenses of a single counsel for all Indemnified Parties with respect to each
such claim, defense thereof, or counterclaims thereto shall be borne by
Indemnifying Party. No Indemnifying Party, in the defense of any such claim or
litigation, shall, except with the consent of each Indemnified Party, consent to
entry of any judgment or enter into any settlement which does not include as an
unconditional term thereof the giving by the claimant or plaintiff to such
Indemnified Party of a release from all liability in respect to such claim or
litigation. Each Indemnified Party shall cooperate to the extent reasonably
required and furnish such information regarding itself or the claim in question
as an Indemnifying Party may reasonably request in writing and as shall be
reasonably required in connection with defense of such claim and litigation
resulting therefrom.

     8.   Information by Holder. Each Holder of Registrable Securities shall
          ---------------------
furnish to the Company such information regarding such Holder and the
distribution proposed by such Holder as the Company may reasonably request in
writing and as shall be reasonably required in connection with any registration,
qualification or compliance referred to in this Agreement and shall promptly
advise the Company in writing of any material changes to such information while
the registration is in effect.

                                       11
<PAGE>

     9.   Transfer or Assignment of Registration Rights. The rights to cause the
          ---------------------------------------------
Company to register securities granted by the Company under this Agreement may
be transferred or assigned by a Holder to a transferee or assignee of any
Registrable Securities, provided that the Company is given written notice at or
prior to the time of said transfer or assignment, stating the name and address
of said transferee or assignee and identifying the securities with respect to
which such registration rights are being transferred or assigned, and provided
further that the transferee or assignee of such rights assumes in writing the
obligations of a Holder under this Agreement to the Company and other Holders in
effect at the time of transfer under all effective agreements.

     10.  Exchange Act Compliance. The Company shall file the reports required
          -----------------------
to be filed by it under the Securities Act and the Exchange Act and the rules
and regulations adopted by the Commission thereunder, to enable holders of
Registrable Securities to sell such securities without registration under the
Securities Act within the limitation of the provisions of (a) Rule 144 under the
Securities Act, as such Rule may be amended from time to time, or (b) any
similar rules or regulations hereunder adopted by the Commission. Upon the
request of any holder of Registrable Securities, the Company will deliver to
such holder a written statement as to whether it has complied with such
requirements.

     11.  Exercise of Warrants.
          --------------------

          (a)  Notwithstanding anything in this Agreement to the contrary, no
Holder shall be required to exercise its Warrant prior to the closing date of a
registration in order for the Warrant Shares to be included in such
registration.

          (b)  The Company agrees to make promptly upon request, and at its
expense, such state "blue sky" filings as it deems necessary or appropriate to
effectuate the exercise of the Warrants. No exercise shall be effectuated until
the necessary "blue sky" filings have been made; provided, however, that no
Holder of a Warrant shall be deprived of any of its rights under this Agreement
due to the Company's failure to timely make its "blue sky" filings and such
Holder's rights to participate in any registration under this Agreement shall be
deemed to be perfected from the date such Holder notifies the Company of its
intention to exercise or convert all or a portion of its Warrants or Notes and
to participate in such registration.

     12.  Liquidated Damages.
          ------------------

          (a)  In the event that the Company fails to use best efforts to comply
with any provision of Section 2, 3 or 4 hereof upon written request of a Holder,
the Company shall within 45 days after the date of receipt by the Company of a
demand from such Holder for payment (the "Payment Demand"), pay to such Holder
as liquidated damages for its noncompliance an amount equal to the Current
Market Price (as defined in subparagraph (b) below) multiplied by (x) the number
of Ordinary Shares proposed to be sold pursuant to the registration or
qualification in question or (y) in the case of a request in accordance with
Section 4 hereof for a shelf registration pursuant to Rule 415 under the
Securities Act, such lesser number of Ordinary Shares as may be specified by the
Initiating Holder(s) in such demand for payment; provided, however, that the
                                                 --------  -------

                                       12
<PAGE>

election of the Initiating Holder(s) to demand payment of liquidated damages
hereunder with respect to less than all of the Ordinary Shares proposed to be
sold pursuant to such shelf registration shall not prevent the Initiating
Holder(s) from any subsequent exercise of registration rights under this
Agreement with respect to the shares of Ordinary Shares for which payment was
not demanded. Payment of such amount shall be made in immediately available
funds. Upon payment to such Holder of such liquidated damages, such Holder shall
assign to the Company the Registrable Securities proposed to be sold pursuant to
the registration or qualification (or such lesser number of Ordinary Shares as
specified in the Payment Demand) in question without any representation or
warranty (other than that the Holder owns all of the right, title and interest
in the Registrable Securities and has not taken any action which would impair
its ownership of or right to transfer to the Company the Registrable
Securities). If such liquidated damages are to be paid with respect to less than
all of the Ordinary Shares issuable upon the exercise of a Warrant, the Company
shall cancel the Warrants and issue in the name of, and deliver to, the Holder,
pursuant to the terms of the Warrants, a new Warrant for the Ordinary Shares
issuable upon the exercise of a Warrant, not required to be assigned to the
Company pursuant to the provisions of the preceding sentence. The Company agrees
that the amount of actual damages that would be sustained by the Holder of
Warrants and/or the Ordinary Shares issuable upon the exercise thereof as a
result of the failure of the Company to use its best efforts to comply with any
provisions of Section 2, 3 or 4 hereof is not capable of ascertainment on any
other basis.

          (b)  "Current Market Price" shall mean (i) the average closing price
per share of Ordinary Shares represented by American Depository Shares for the
forty-five (45) consecutive trading days beginning on the Determination Date.
"Determination Date" shall mean, with respect to a requested registration
pursuant to Section 2 or 3 of this Agreement, the date which is forty-five (45)
days after the date of such request, and with respect to a requested
registration pursuant to Section 4 of this Agreement, the date which is thirty
(30) days after the date of such request. The closing price for each day shall
be as reported in The Wall Street Journal or, if not reported therein, as
reported in another newspaper of national circulation chosen by the Board of
Directors of the Company, the average of the last reported sales price for such
shares in the over-the-counter market, as reported on the National Association
of Securities Dealers Automated Quotation System, or, if such sales prices shall
not be reported thereon, the average of the closing bid and asked prices so
reported, or, if such bid and asked prices shall not be reported thereon, as the
same shall be reported by the National Quotation Bureau Incorporated, or, if
such firm at the time is not engaged in the business of reporting such prices,
as furnished by any similar firm then engaged in such business and selected by
the Company or, if there is no such firm, as furnished by any member of the
National Association of Securities Dealers, Inc., selected by the Company or
(ii) if the Company shall no longer have a class of equity securities registered
under the Securities Exchange Act of 1934, as amended, "Current Market Price"
shall be determined as follows: first, by a nationally recognized investment
                                -----
banking firm selected by the holders of a majority of the Registrable Securities
requested to be included in such registration, which determination shall be made
within thirty (30) days after the delivery of the demand for payment, second, if
                                                                      ------
such determination shall not be satisfactory to the Company, as evidenced by a
written objection by the Company to the holders of the Registrable Securities
requested to be included in such registration, within ten (10) days of receipt
by the Company of such determination, the Company shall be entitled to select a
nationally recognized investment banking firm which shall make its own
determination within thirty (30) days of its

                                       13
<PAGE>

appointment, and if such determination shall differ by less than 10% from the
determination of the nationally recognized investment banking firm selected by
the holders of a majority of the Registrable Securities requested to be included
in such registration, the Current Market Price shall be the average of such
determinations and, third, if such determinations shall differ by 10% or more,
                    -----
such investment banking firms shall appoint a third nationally recognized
investment banking firm which shall make its own determination within two weeks
of its appointment, which determination shall be binding upon the Company and
the holders of the Registrable Securities requested to be included in such
registration. Any and all determinations made pursuant to this Section 12(b)(ii)
shall be performed by an investment banking firm experienced in the conduct of
corporate valuations and shall be based upon the fair market value of 100% of
the Company on a consolidated basis if sold as a going concern, without giving
effect to any discount for lack of liquidity of the Ordinary Shares or to the
fact that the Ordinary Shares are privately held or that the Company has no
class of equity securities registered under the Securities Exchange Act of 1934,
as amended, or to any discount relating to, the right of any stockholder or
warrant holder of the Company to receive payment pursuant to this Section 12. In
addition, in making such determination, the investment banking firm shall take
into account the valuations associated with recent public offerings of Ordinary
Shares by companies engaged in businesses and with capital structures similar to
the Company and such other matters as are relevant to the valuation of the
Company.

     13.  No Conflict of Rights.
          ---------------------

          (a)  The Company will not hereafter enter into any agreement with
respect to its securities which is inconsistent with the rights (including, but
not limited to, priority rights) granted to the Holders in this Agreement.
Without limiting the generality of the foregoing, the Company will not hereafter
enter into any agreement with respect to its securities which grants or modifies
any existing agreement with respect to its securities to grant to the holder of
its securities in connection with an incidental registration of such securities
equal or higher priority to the rights granted to the Holders under Sections 2,
3 and 4 of this Agreement.

          (b)  In addition, the Company hereby covenants and agrees to cause all
of its stockholders to which it grants registration rights after the date hereof
to acknowledge in writing the priorities and limitations of inclusion of
securities set forth in this Agreement.

     14.  Benefits of Agreement; Successors and Assigns. This Agreement shall be
          ---------------------------------------------
binding upon and inure to the benefit of the parties and their respective
successors and permitted assigns, legal representatives and heirs. This
Agreement does not create, and shall not be construed as creating any rights
enforceable by any other Person.

     15.  Complete Agreement. This Agreement constitutes the complete
          ------------------
understanding among the parties with respect to its subject matter and
supersedes all existing agreements and understandings, whether oral or written,
among them. No alteration or modification of any provisions of this Agreement
shall be valid unless made in writing and signed, on the one hand, by the
Holders of a majority of the Registrable Securities then outstanding and, on the
other, by the Company.

                                       14
<PAGE>

     16.  Section Headings. The section headings contained in this Agreement are
          ----------------
for reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.

     17.  Notices. (a) All notices, offers, acceptances and other communications
          -------
required or permitted to be given or to otherwise be made to any party to this
Agreement shall be deemed to be sufficient if contained in a written instrument
delivered by hand, first class mail (registered or certified, return receipt
requested), telex, telecopier or overnight air courier guaranteeing next day
delivery, if to the Company, at 620 Airport Road, Napa, California, Attention:
Chief Executive Officer, and if to any Holder, at the address of such Holder as
set forth in the stock transfer books of the Corporation.

          (b)  All such notices and communications shall be deemed to have been
duly given: at the time delivered by hand, if personally delivered; five
business days after being deposited in the mail, postage prepaid, if mailed;
when answered back, if telexed; when receipt acknowledged, if telecopied; and
the next business day after timely delivery to the courier, if sent by overnight
air courier guaranteeing next day delivery. Any party may change the address to
which each such notice or communication shall be sent by giving written notice
to the other parties of such new address in the manner provided herein for
giving notice.

     18.  Governing Law. This Agreement shall be governed by, and construed and
          -------------
enforced in accordance with, the laws of the State of New York without giving
effect to the provisions, policies or principles (hereof respecting conflict or
choice of laws.

     19.  Counterparts. This Agreement may be executed in one or more
          ------------
counterparts each of which shall be deemed an original but all of which taken
together shall constitute one and the same agreement.

     20.  Severability. Any provision of this Agreement which is determined to
          ------------
be illegal, prohibited or unenforceable in any jurisdiction shall, as to such
jurisdiction, be ineffective to the extent of such illegality, prohibition or
unenforceability without invalidating the remaining provisions hereof which
shall be severable and enforceable according to their terms and any such
prohibition or unenforceability in any jurisdiction shall not invalidate or
render unenforceable such provision in any other jurisdiction.

                                       15
<PAGE>

     IN WITNESS WHEREOF, the parties have signed this Amended and Restated
Registration Rights Agreement as of the date first set forth above.

                                  SENETEK PLC

                                  By: /s/ Frank J. Massino
                                      --------------------
                                   Name:  Frank J. Massino
                                   Title: President

                                  SILVER CREEK INVESTMENTS, LTD.

                                  By: /s/ Robert T. Tucker
                                     ---------------------
                                   Name:  Robert T. Tucker
                                   Title: Director

                                  BOMOSEEN INVESTMENTS, LTD.

                                  By: /s/ Robert T. Tucker
                                     ---------------------
                                   Name:  Robert T. Tucker
                                   Title: Director

                                  ELSTREE HOLDINGS, LTD.

                                  By: /s/ Robert T. Tucker
                                     ---------------------
                                   Name:  Robert T. Tucker
                                   Title: Attorney-in-Fact

                                 DANDELION INVESTMENTS, LTD.

                                  By: /s/ Robert T. Tucker
                                     ---------------------
                                   Name:  Robert T. Tucker
                                   Title: Attorney-in-Fact

                                 SCORPION HOLDINGS, INC.

                                  By: /s/ N. Brandolini
                                     ------------------
                                   Name:  N. Brandolini
                                   Title: CEO

                                 WALLINGTON INVESTMENTS LIMITED

                                  By: /s/ Nancy Main
                                     ---------------
                                   Name:  Nancy Main
                                   Title: Attorney-in-Fact

                                       16

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00027-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00027-of-00352.parquet"}]]