<PAGE>

                                                                     EXHIBIT 4.3

                             JUNIPER NETWORKS, INC.

                              AMENDED AND RESTATED
                                 1996 STOCK PLAN
                      (As amended through January 1, 2004)

      1. Purposes of the Plan. The purposes of this Stock Plan are to attract
and retain the best available personnel for positions of substantial
responsibility, to provide additional incentive to Employees and Consultants of
the Company and its Subsidiaries and to promote the success of the Company's
business. Options granted under the Plan may be Incentive Stock Options or
Nonstatutory Stock Options, as determined by the Administrator at the time of
grant of an Option and subject to the applicable provisions of Section 422 of
the Code and the regulations promulgated thereunder. Stock Purchase Rights may
also be granted under the Plan.

      2. Definitions. As used herein, the following definitions shall apply:

            (a) "Administrator" means the Board or any of its Committees
appointed pursuant to Section 4 of the Plan.

            (b) "Applicable Laws" means the legal requirements relating to the
administration of stock option plans under U.S. state corporate laws, U.S.
federal and state securities laws, the Code and the applicable laws of any
foreign country or jurisdiction where Options or Stock Purchase Rights are, or
will be, granted under the Plan.

            (c) "Board" means the Board of Directors of the Company.

            (d) "Code" means the Internal Revenue Code of 1986, as amended.

            (e) "Committee" means a Committee appointed by the Board of
Directors in accordance with Section 4 of the Plan.

            (f) "Common Stock" means the Common Stock of the Company.

            (g) "Company" means Juniper Networks, Inc., a Delaware corporation.

            (h) "Consultant" means any person who is engaged by the Company or
any Parent or Subsidiary to render consulting or advisory services to such
entities.

            (i) "Continuous Status as an Employee or Consultant" means that the
employment or consulting relationship with the Company, any Parent or Subsidiary
is not interrupted or terminated. Continuous Status as an Employee or Consultant
shall not be considered interrupted in the case of (i) any leave of absence
approved by the Company (provided, however, that the Administrator shall be
permitted to stop vesting on any leave of absence, on an individual, aggregate
or policy basis, even if

<PAGE>

                                                                     EXHIBIT 4.3

such leave of absence is approved by the Company) or (ii) transfers between
locations of the Company or between the Company, its Parent, any Subsidiary, or
any successor. A leave of absence approved by the Company shall include sick
leave, military leave, or any other personal leave approved by an authorized
representative of the Company. For purposes of Incentive Stock Options, no such
leave may exceed 90 days, unless reemployment upon expiration of such leave is
guaranteed by statute or contract, including Company policies. If reemployment
upon expiration of a leave of absence approved by the Company is not so
guaranteed, on the 181st day of such leave any Incentive Stock Option held by
the Optionee shall cease to be treated as an Incentive Stock Option and shall be
treated for tax purposes as a Nonstatutory Stock Option.

            (j) "Director" means a member of the Board of Directors of the
Company.

            (k) "Employee" means any person, including Officers and Directors,
employed by the Company or any Parent or Subsidiary of the Company. The payment
of a Director's fee by the Company shall not be sufficient to constitute
"employment" by the Company.

            (l) "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

            (m) "Fair Market Value" means, as of any date, the value of Common
Stock determined as follows:

                  (i) If the Common Stock is listed on any established stock
exchange or a national market system, including without limitation the Nasdaq
National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its
Fair Market Value shall be the closing sales price for such stock (or the
closing bid, if no sales were reported) as quoted on such exchange or system for
the last market trading day prior to the time of determination, as reported in
The Wall Street Journal or such other source as the Administrator deems
reliable;

                  (ii) If the Common Stock is regularly quoted by a recognized
securities dealer but selling prices are not reported, its Fair Market Value
shall be the mean between the high bid and low asked prices for the Common Stock
on the last market trading day prior to the day of determination; or

                  (iii) In the absence of an established market for the Common
Stock, the Fair Market Value thereof shall be determined in good faith by the
Administrator.

            (n) "Incentive Stock Option" means an Option intended to qualify as
an incentive stock option within the meaning of Section 422 of the Code.

            (o) "Nonstatutory Stock Option" means an Option not intended to
qualify as an Incentive Stock Option.

            (p) "Officer" means a person who is an officer of the Company within
the meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

                                      -2-
<PAGE>

                                                                     EXHIBIT 4.3

            (q) "Option" means a stock option granted pursuant to the Plan.

            (r) "Optioned Stock" means the Common Stock subject to an Option or
a Stock Purchase Right.

            (s) "Optionee" means an Employee or Consultant who receives an
Option or Stock Purchase Right.

            (t) "Parent" means a "parent corporation," whether now or hereafter
existing, as defined in Section 424(e) of the Code.

            (u) "Plan" means this 1996 Stock Plan.

            (v) "Restricted Stock" means shares of Common Stock acquired
pursuant to a grant of a Stock Purchase Right under Section 11 below.

            (w) "Section 16(b)" means Section 16(b) of the Securities Exchange
Act of 1934, as amended.

            (x) "Share" means a share of the Common Stock, as adjusted in
accordance with Section 12 below.

            (y) "Stock Purchase Right" means a right to purchase Common Stock
pursuant to Section 11 below.

            (z) "Subsidiary" means a "subsidiary corporation," whether now or
hereafter existing, as defined in Section 424(f) of the Code.

      3. Stock Subject to the Plan. Subject to the provisions of Section 12 of
the Plan, the maximum aggregate number of Shares which may be subject to option
and sold under the Plan is 164,263,039 Shares, plus an annual increase to be
added on the first day of the Company's fiscal year beginning in 2000 equal to
the lesser of (i) 18,000,000 shares, (ii) 5% of the outstanding shares on such
date or (iii) a lesser amount determined by the Board. The Shares may be
authorized but unissued, or reacquired Common Stock.

            If an Option or Stock Purchase Right expires or becomes
unexercisable without having been exercised in full, or is surrendered pursuant
to an option exchange program, the unpurchased Shares which were subject thereto
shall become available for future grant or sale under the Plan (unless the Plan
has terminated). However, Shares that have actually been issued under the Plan,
upon exercise of either an Option or Stock Purchase Right, shall not be returned
to the Plan and shall not become available for future distribution under the
Plan, except that if Shares of Restricted Stock are repurchased by the Company
at their original purchase price, and the original purchaser of such Shares did
not receive any benefits of ownership of such Shares, such Shares shall become
available for future grant under the Plan.

                                      -3-
<PAGE>

                                                                     EXHIBIT 4.3

For purposes of the preceding sentence, voting rights shall not be considered a
benefit of Share ownership.

      4. Administration of the Plan.

            (a) Procedure.

                  (i) Multiple Administrative Bodies. The Plan may be
administered by different Committees with respect to different groups of Service
Providers.

                  (ii) Section 162(m). To the extent that the Administrator
determines it to be desirable to qualify Options granted hereunder as
"performance-based compensation" within the meaning of Section 162(m) of the
Code, the Plan shall be administered by a Committee of two or more "outside
directors" within the meaning of Section 162(m) of the Code.

                  (iii) Rule 16b-3 . To the extent desirable to qualify
transactions hereunder as exempt under Rule 16b-3, the transactions contemplated
hereunder shall be structured to satisfy the requirements for exemption under
Rule 16b-3.

                  (iv) Other Administration. Other than as provided above, the
Plan shall be administered by (A) the Board or (B) a Committee, which committee
shall be constituted to satisfy Applicable Laws.

            (b) Powers of the Administrator. Subject to the provisions of the
Plan and, in the case of a Committee, the specific duties delegated by the Board
to such Committee, and subject to the approval of any relevant authorities,
including the approval, if required, of any stock exchange upon which the Common
Stock is listed, the Administrator shall have the authority in its discretion:

                  (i) to determine the Fair Market Value of the Common Stock, in
accordance with Section 2(m) of the Plan;

                  (ii) to select the Consultants and Employees to whom Options
and Stock Purchase Rights may from time to time be granted hereunder;

                  (iii) to determine whether and to what extent Options and
Stock Purchase Rights or any combination thereof are granted hereunder;

                  (iv) to determine the number of Shares to be covered by each
such award granted hereunder;

                  (v) to approve forms of agreement for use under the Plan;

                  (vi) to determine the terms and conditions of any award
granted hereunder;

                                      -4-
<PAGE>

                                                                     EXHIBIT 4.3

                  (vii) to determine whether and under what circumstances an
Option may be settled in cash under subsection 9(f) instead of Common Stock;

                  (viii) to reduce the exercise price of any Option to the then
current Fair Market Value if the Fair Market Value of the Common Stock covered
by such Option has declined since the date the Option was granted; and

                  (ix) to construe and interpret the terms of the Plan and
awards granted pursuant to the Plan.

            (c) Effect of Administrator's Decision. All decisions,
determinations and interpretations of the Administrator shall be final and
binding on all Optionees and any other holders of any Options or Stock Purchase
Rights.

      5. Eligibility.

            (a) Nonstatutory Stock Options and Stock Purchase Rights may be
granted to Employees, Consultants and Directors. Incentive Stock Options may be
granted only to Employees. An Employee or Consultant who has been granted an
Option or Stock Purchase Right may, if otherwise eligible, be granted additional
Options or Stock Purchase Rights.

            (b) Each Option shall be designated in the written option agreement
as either an Incentive Stock Option or a Nonstatutory Stock Option. However,
notwithstanding such designation, to the extent that the aggregate Fair Market
Value of the Shares with respect to which Incentive Stock Options are
exercisable for the first time by the Optionee during any calendar year (under
all plans of the Company and any Parent or Subsidiary) exceeds $100,000, such
Options shall be treated as Nonstatutory Stock Options. For purposes of this
Section 5(b), Incentive Stock Options shall be taken into account in the order
in which they were granted. The Fair Market Value of the Shares shall be
determined as of the time the Option with respect to such Shares is granted.

            (c) Neither the Plan nor any Option or Stock Purchase Right shall
confer upon any Optionee any right with respect to continuation of his or her
employment or consulting relationship with the Company, nor shall it interfere
in any way with his or her right or the Company's right to terminate his or her
employment or consulting relationship at any time, with or without cause.

            (d) The following limitations shall apply to grants of Options to
Employees:

                  (i) No Employee shall be granted, in any fiscal year of the
Company, Options to purchase more than 6,000,000 Shares.

                                      -5-
<PAGE>

                                                                     EXHIBIT 4.3

                  (ii) In connection with his or her initial employment, an
Employee may be granted Options to purchase up to an additional 12,000,000
Shares which shall not count against the limit set forth in subsection (i)
above.

                  (iii) The foregoing limitations shall be adjusted
proportionately in connection with any change in the Company's capitalization as
described in Section 12.

                  (iv) If an Option is cancelled in the same fiscal year of the
Company in which it was granted (other than in connection with a transaction
described in Section 12), the cancelled Option shall be counted against the
limit set forth in subsection (i) above. For this purpose, if the exercise price
of an Option is reduced, such reduction will be treated as a cancellation of the
Option and the grant of a new Option.

      6. Term of Plan. The Plan shall become effective upon the earlier to occur
of its adoption by the Board of Directors or its approval by the shareholders of
the Company, as described in Section 18 of the Plan. It shall continue in effect
for a term of ten (10) years unless sooner terminated under Section 14 of the
Plan.

      7. Term of Option. The term of each Option shall be the term stated in the
Option Agreement; provided, however, that the term shall be no more than ten
(10) years from the date of grant thereof. In the case of an Incentive Stock
Option granted to an Optionee who, at the time the Option is granted, owns stock
representing more than ten percent (10%) of the voting power of all classes of
stock of the Company or any Parent or Subsidiary, the term of the Option shall
be five (5) years from the date of grant thereof or such shorter term as may be
provided in the Option Agreement.

      8. Option Exercise Price and Consideration.

            (a) The per share exercise price for the Shares to be issued upon
exercise of an Option shall be such price as is determined by the Administrator,
but shall be subject to the following:

                  (i) In the case of an Incentive Stock Option

                        (A) granted to an Employee who, at the time of grant of
such Option, owns stock representing more than ten percent (10%) of the voting
power of all classes of stock of the Company or any Parent or Subsidiary, the
per Share exercise price shall be no less than 110% of the Fair Market Value per
Share on the date of grant.

                        (B) granted to any other Employee, the per Share
exercise price shall be no less than 100% of the Fair Market Value per Share on
the date of grant.

                  (ii) In the case of a Nonstatutory Stock Option, the per Share
exercise price shall be determined by the Administrator. In the case of a
Nonstatutory Stock Option intended to qualify as

                                      -6-
<PAGE>

                                                                     EXHIBIT 4.3

"performance-based compensation" within the meaning of Section 162(m) of the
Code, the per Share exercise price shall be no less than 100% of the Fair Market
Value per Share on the date of grant.

            (b) The consideration to be paid for the Shares to be issued upon
exercise of an Option, including the method of payment, shall be determined by
the Administrator (and, in the case of an Incentive Stock Option, shall be
determined at the time of grant). Such consideration may consist of (1) cash,
(2) check, (3) promissory note, (4) other Shares which (x) in the case of Shares
acquired upon exercise of an Option, have been owned by the Optionee for more
than six months on the date of surrender, and (y) have a Fair Market Value on
the date of surrender equal to the aggregate exercise price of the Shares as to
which such Option shall be exercised, (5) delivery of a properly executed
exercise notice together with such other documentation as the Administrator and
a broker, if applicable, shall require to effect an exercise of the Option and
delivery to the Company of the sale or loan proceeds required to pay the
exercise price, (6) any other consideration permitted by applicable law, or (7)
any combination of the foregoing methods of payment. In making its determination
as to the type of consideration to accept, the Administrator shall consider if
acceptance of such consideration may be reasonably expected to benefit the
Company.

      9. Exercise of Option.

            (a) Procedure for Exercise; Rights as a Shareholder. Any Option
granted hereunder shall be exercisable at such times and under such conditions
as determined by the Administrator, including performance criteria with respect
to the Company and/or the Optionee, and as shall be permissible under the terms
of the Plan.

                  An Option may not be exercised for a fraction of a Share.

                  An Option shall be deemed to be exercised when written notice
of such exercise has been given to the Company in accordance with the terms of
the Option by the person entitled to exercise the Option and full payment for
the Shares with respect to which the Option is exercised has been received by
the Company. Full payment may, as authorized by the Administrator, consist of
any consideration and method of payment allowable under Section 8(b) hereof.
Until the issuance (as evidenced by the appropriate entry on the books of the
Company or of a duly authorized transfer agent of the Company) of the stock
certificate evidencing such Shares, no right to vote, receive dividends or any
other rights as a shareholder shall exist with respect to the Optioned Stock,
notwithstanding the exercise of the Option. The Company shall issue (or cause to
be issued) such stock certificate promptly upon exercise of the Option. No
adjustment shall be made for a dividend or other right for which the record date
is prior to the date the stock certificate is issued, except as provided in
Section 12 hereof.

                  Exercise of an Option in any manner shall result in a decrease
in the number of Shares which thereafter may be available, both for purposes of
the Plan and for sale under the Option, by the number of Shares as to which the
Option is exercised.

                                      -7-
<PAGE>

                                                                     EXHIBIT 4.3

            (b) Termination of Employment or Consulting Relationship. In the
event of termination of an Optionee's Continuous Status as an Employee or
Consultant (but not in the event of an Optionee's change of status from Employee
to Consultant (in which case an Employee's Incentive Stock Option shall
automatically convert to a Nonstatutory Stock Option on the date three (3)
months and one day following such change of status) or from Consultant to
Employee), such Optionee may, but only within such period of time as is
determined by the Administrator, with such determination in the case of an
Incentive Stock Option not exceeding thirty (30) days after the date of such
termination (but in no event later than the expiration date of the term of such
Option as set forth in the Option Agreement), exercise his or her Option to the
extent that the Optionee was entitled to exercise it at the date of such
termination. To the extent that the Optionee was not entitled to exercise the
Option at the date of such termination, or if the Optionee does not exercise
such Option to the extent so entitled within the time specified herein, the
Option shall terminate.

            (c) Disability of Optionee. In the event of termination of an
Optionee's Continuous Status as an Employee or Consultant as a result of his or
her disability, the Optionee may, but only within ninety (90) days from the date
of such termination (and in no event later than the expiration date of the term
of such Option as set forth in the Option Agreement), exercise the Option to the
extent otherwise entitled to exercise it at the date of such termination. If
such disability is not a "disability" as such term is defined in Section
22(e)(3) of the Code, in the case of an Incentive Stock Option such Incentive
Stock Option shall automatically cease to be treated as an Incentive Stock
Option and shall be treated for tax purposes as a Nonstatutory Stock Option on
the day three months and one day following such termination. To the extent that
the Optionee was not entitled to exercise the Option at the date of termination,
or if the Optionee does not exercise such Option to the extent so entitled
within the time specified herein, the Option shall terminate, and the Shares
covered by such Option shall revert to the Plan.

            (d) Death of Optionee. In the event of the death of an Optionee, the
Option may be exercised at any time within ninety (90) days following the date
of death (but in no event later than the expiration of the term of such Option
as set forth in the Notice of Grant) by the Optionee's estate or by a person who
acquired the right to exercise the Option by bequest or inheritance, but only to
the extent that the Optionee was entitled to exercise the Option on the date of
death. If, at the time of death, the Optionee was not entitled to exercise his
or her entire Option, the Shares covered by the unexercisable portion of the
Option shall immediately revert to the Plan. If, after the Optionee's death, the
Optionee's estate or a person who acquires the right to exercise the Option by
bequest or inheritance does not exercise the Option within the time specified
herein, the Option shall terminate, and the Shares covered by such Option shall
revert to the Plan.

            (e) Buyout Provisions. The Administrator may at any time offer to
buy out for a payment in cash or Shares, an Option previously granted, based on
such terms and conditions as the Administrator shall establish and communicate
to the Optionee at the time that such offer is made.

      10. Non-Transferability of Options and Stock Purchase Rights. Options and
Stock Purchase Rights may not be sold, pledged, assigned, hypothecated,
transferred, or disposed of in any manner other

                                      -8-
<PAGE>

                                                                     EXHIBIT 4.3

than by will or by the laws of descent or distribution and may be exercised,
during the lifetime of the Optionee, only by the Optionee.

      11. Stock Purchase Rights.

            (a) Rights to Purchase. Stock Purchase Rights may be issued either
alone, in addition to, or in tandem with other awards granted under the Plan
and/or cash awards made outside of the Plan. After the Administrator determines
that it will offer Stock Purchase Rights under the Plan, it shall advise the
offeree in writing of the terms, conditions and restrictions related to the
offer, including the number of Shares that such person shall be entitled to
purchase, the price to be paid, and the time within which such person must
accept such offer, which shall in no event exceed thirty (30) days from the date
upon which the Administrator makes the determination to grant the Stock Purchase
Right. The offer shall be accepted by execution of a Restricted Stock purchase
agreement in the form determined by the Administrator. Shares purchased pursuant
to the grant of a Stock Purchase Right shall be referred to herein as
"Restricted Stock."

            (b) Repurchase Option. Unless the Administrator determines
otherwise, the Restricted Stock purchase agreement shall grant the Company a
repurchase option exercisable upon the voluntary or involuntary termination of
the purchaser's employment with the Company for any reason (including death or
disability). The purchase price for Shares repurchased pursuant to the
Restricted Stock purchase agreement shall be the original price paid by the
purchaser and may be paid by cancellation of any indebtedness of the purchaser
to the Company. The repurchase option shall lapse at such rate as the
Administrator may determine.

            (c) Other Provisions. The Restricted Stock purchase agreement shall
contain such other terms, provisions and conditions not inconsistent with the
Plan as may be determined by the Administrator in its sole discretion. In
addition, the provisions of Restricted Stock purchase agreements need not be the
same with respect to each purchaser.

            (d) Rights as a Shareholder. Once the Stock Purchase Right is
exercised, the purchaser shall have rights equivalent to those of a shareholder
and shall be a shareholder when his or her purchase is entered upon the records
of the duly authorized transfer agent of the Company. No adjustment shall be
made for a dividend or other right for which the record date is prior to the
date the Stock Purchase Right is exercised, except as provided in Section 12 of
the Plan.

      12. Adjustments Upon Changes in Capitalization or Merger.

            (a) Changes in Capitalization. Subject to any required action by the
shareholders of the Company, the number of shares of Common Stock covered by
each outstanding Option or Stock Purchase Right, and the number of shares of
Common Stock which have been authorized for issuance under the Plan but as to
which no Options or Stock Purchase Rights have yet been granted or which have
been returned to the Plan upon cancellation or expiration of an Option or Stock
Purchase

                                      -9-
<PAGE>

                                                                     EXHIBIT 4.3

Right, as well as the price per share of Common Stock covered by each such
outstanding Option or Stock Purchase Right, shall be proportionately adjusted
for any increase or decrease in the number of issued shares of Common Stock
resulting from a stock split, reverse stock split, stock dividend, combination
or reclassification of the Common Stock, or any other increase or decrease in
the number of issued shares of Common Stock effected without receipt of
consideration by the Company. The conversion of any convertible securities of
the Company shall not be deemed to have been "effected without receipt of
consideration." Such adjustment shall be made by the Board, whose determination
in that respect shall be final, binding and conclusive. Except as expressly
provided herein, no issuance by the Company of shares of stock of any class, or
securities convertible into shares of stock of any class, shall affect, and no
adjustment by reason thereof shall be made with respect to, the number or price
of shares of Common Stock subject to an Option or Stock Purchase Right.

            (b) Dissolution or Liquidation. In the event of the proposed
dissolution or liquidation of the Company, the Administrator shall notify the
Optionee at least fifteen (15) days prior to such proposed action. To the extent
it has not been previously exercised, the Option or Stock Purchase Right shall
terminate immediately prior to the consummation of such proposed action.

            (c) Merger. In the event of a merger of the Company with or into
another corporation, each outstanding Option or Stock Purchase Right may be
assumed or an equivalent option or right may be substituted by such successor
corporation or a parent or subsidiary of such successor corporation. If, in such
event, an Option or Stock Purchase Right is not assumed or substituted, the
Option or Stock Purchase Right shall terminate as of the date of the closing of
the merger. For the purposes of this paragraph, the Option or Stock Purchase
Right shall be considered assumed if, following the merger, the Option or Stock
Purchase Right confers the right to purchase or receive, for each Share of
Optioned Stock subject to the Option or Stock Purchase Right immediately prior
to the merger, the consideration (whether stock, cash, or other securities or
property) received in the merger by holders of Common Stock for each Share held
on the effective date of the transaction (and if the holders are offered a
choice of consideration, the type of consideration chosen by the holders of a
majority of the outstanding Shares). If such consideration received in the
merger is not solely common stock of the successor corporation or its Parent,
the Administrator may, with the consent of the successor corporation, provide
for the consideration to be received upon the exercise of the Option or Stock
Purchase Right, for each Share of Optioned Stock subject to the Option or Stock
Purchase Right, to be solely common stock of the successor corporation or its
Parent equal in fair market value to the per share consideration received by
holders of Common Stock in the merger.

      13. Time of Granting Options and Stock Purchase Rights. The date of grant
of an Option or Stock Purchase Right shall, for all purposes, be the date on
which the Administrator makes the determination granting such Option or Stock
Purchase Right, or such other date as is determined by the Administrator. Notice
of the determination shall be given to each Employee or Consultant to whom an
Option or Stock Purchase Right is so granted within a reasonable time after the
date of such grant.

      14. Amendment and Termination of the Plan.

                                      -10-
<PAGE>

                                                                     EXHIBIT 4.3

            (a) Amendment and Termination. The Board may at any time amend,
alter, suspend or discontinue the Plan, but no amendment, alteration, suspension
or discontinuation shall be made which would impair the rights of any Optionee
under any grant theretofore made, without his or her consent. In addition, to
the extent necessary and desirable to comply with Rule 16b-3 under the Exchange
Act or with Section 422 of the Code (or any other applicable law or regulation,
including the requirements of the NASD or an established stock exchange), the
Company shall obtain shareholder approval of any Plan amendment in such a manner
and to such a degree as required.

            (b) Effect of Amendment or Termination. Any such amendment or
termination of the Plan shall not affect Options or Stock Purchase Rights
already granted, and such Options and Stock Purchase Rights shall remain in full
force and effect as if this Plan had not been amended or terminated, unless
mutually agreed otherwise between the Optionee and the Administrator, which
agreement must be in writing and signed by the Optionee and the Company.

      15. Conditions Upon Issuance of Shares. Shares shall not be issued
pursuant to the exercise of an Option or Stock Purchase Right unless the
exercise of such Option or Stock Purchase Right and the issuance and delivery of
such Shares pursuant thereto shall comply with all relevant provisions of law,
including, without limitation, the Securities Act of 1933, as amended, the
Exchange Act, the rules and regulations promulgated thereunder, and the
requirements of any stock exchange upon which the Shares may then be listed, and
shall be further subject to the approval of counsel for the Company with respect
to such compliance.

            As a condition to the exercise of an Option or Stock Purchase Right,
the Company may require the person exercising such Option or Stock Purchase
Right to represent and warrant at the time of any such exercise that the Shares
are being purchased only for investment and without any present intention to
sell or distribute such Shares if, in the opinion of counsel for the Company,
such a representation is required by any of the aforementioned relevant
provisions of law.

      16. Reservation of Shares. The Company, during the term of this Plan,
shall at all times reserve and keep available such number of Shares as shall be
sufficient to satisfy the requirements of the Plan.

            The inability of the Company to obtain authority from any regulatory
body having jurisdiction, which authority is deemed by the Company's counsel to
be necessary to the lawful issuance and sale of any Shares hereunder, shall
relieve the Company of any liability in respect of the failure to issue or sell
such Shares as to which such requisite authority shall not have been obtained.

      17. Agreements. Options and Stock Purchase Rights shall be evidenced by
written agreements in such form as the Administrator shall approve from time to
time.

      18. Shareholder Approval. Continuance of the Plan shall be subject to
approval by the shareholders of the Company within twelve (12) months before or
after the date the Plan is adopted. Such shareholder approval shall be obtained
in the degree and manner required under Applicable Laws and the rules of any
stock exchange upon which the Common Stock is listed.

                                      -11-
<PAGE>

                                                                     EXHIBIT 4.3

                                    * * * * *

                                      -12-
<PAGE>

                                                                     EXHIBIT 4.3

                                  PLAN HISTORY

<TABLE>
<S>                                       <C>                        <C>
Initial Shares Granted                      3,600,000                06/12/96

Additional Shares                           1,150,000                01/16/97

Three for Two Stock Split                   2,375,000                06/27/97

Additional Shares                           2,000,000                11/19/97

Three for Two Stock Split                   4,562,500                10/02/98

Additional Shares                           3,000,000                11/12/98

Additional Shares                           3,000,000                04/19/99

Annual Increase                             2,098,963                01/01/00

Three for One Stock Split                  43,572,926                01/15/00

Two for One Stock Split                    65,359,389                06/15/00

Annual Increase                            15,904,261                01/01/01

Annual Increase                            18,000,000                01/01/04

TOTAL AUTHORIZED                          164,263,039
</TABLE>