AMERICAN TOWER SYSTEMS CORPORATION

                             1997 STOCK OPTION PLAN

1.   PURPOSE

     The purpose of this 1997 Stock Option Plan (the "Plan") is to encourage
directors, consultants and employees of American Tower Systems Corporation (the
"Company") and its Subsidiaries (as hereinafter defined) to continue their
association with the Company and its Subsidiaries, by providing opportunities
for such persons to participate in the ownership of the Company and in its
future growth through the granting of stock options (the "Options") which may be
options designed to qualify as incentive stock options (within the meaning of
Section 422 of the Internal Revenue Code of 1986, as amended (the "Code") (an
"ISO"), or options not intended to qualify for any special tax treatment under
the Code (a "NQO").  The term "Subsidiary" as used in the Plan means a
corporation or other business organization of which the Company owns, directly
or indirectly through an unbroken chain of ownership, fifty percent (50%) or
more of the total combined voting power of all classes of stock.

2.   ADMINISTRATION OF THE PLAN

     The Plan shall be administered by a committee (the "Committee") consisting
of two or more members of the Company's Board of Directors (the "Board").  The
Committee shall from time to time determine to whom options or other rights
shall be granted under the Plan, whether options granted shall be incentive
stock options ("ISOs") or nonqualified stock options ("NSOs"), the terms of the
options or other rights, and the number of shares that may be granted under
options.  The Committee shall report to the Board the names of individuals to
whom stock or options or other rights are to be granted, the number of shares
covered, and the terms and conditions of each grant. The determinations
described in this Section 2 may be made by the Committee or by the Board, as the
Board shall direct in its discretion, and references in the Plan to the
Committee shall be understood to refer to the Board in any such case.

     The Committee shall select one of its members as Chairman and shall hold
meetings at such times and places as it may determine.  A majority of the
Committee shall constitute a quorum, and acts of the Committee at which a quorum
is present, or acts reduced to or approved in writing by all the members of the
Committee, shall be the valid acts of the Committee.  The Committee shall have
the authority to adopt, amend, and rescind such rules and regulations as, in its
opinion, may be advisable in the administration of the Plan.  All questions of
interpretation and application of such rules and regulations, of the Plan and of
options granted thereunder (the "Options"), shall be subject to the
determination of the Committee, which shall be final and binding.  The Plan
shall be administered in such a manner as to permit those Options granted
hereunder and specially designated under Section 5 hereof as an ISO to qualify
as incentive stock options as described in Section 422 of the Internal Revenue
Code of 1986, as amended (the "Code").

     For so long as Section 16 of the Securities Exchange Act of 1934, as
amended from time to time (the "Exchange Act"), is applicable to the Company,
each member of the Committee shall be a "non-employee director" or the
equivalent within the meaning of Rule


16b-3 under the Exchange Act, and, for so long as Section 162(m) of the Code is
applicable to the Company, an "outside director" within the meaning of Section
162 of the Code and the regulations thereunder.

     With respect to persons subject to Section 16 of the Exchange Act
("Insiders"), transactions under the Plan are intended to comply with all
applicable conditions of Rule 16b-3 or its successor under the Exchange Act.  To
the extent any provision of the Plan or action by the Committee fails to so
comply, it shall be deemed to be modified so as to be in compliance with such
Rule, or, if such modification is not possible, it shall be deemed to be null
and void, to the extent permitted by law and deemed advisable by the Committee.

3.   OPTION SHARES

     The stock subject to Options under the Plan shall be shares of Class A and
Class B Common Stock, par value $.01 per share (the "Stock"), provided, however,
that after the consummation of the ATC Merger as defined in the Agreement and
Plan of Merger by and between the Company and American Tower Corporation, dated
December 12, 1997, as may be amended, any Options granted shall be for shares of
Class A.  The total amount of the Stock with respect to which Options may be
granted (the "Option Pool"), shall not exceed in the aggregate 24,000,000
shares; provided, however, and subject to the limitation below regarding shares
available for grants of ISOs, the number of shares authorized for issuance under
the Plan shall increase each September 30, commencing September 30, 2001, by an
amount equal to the lesser of:

(i)  the number of shares of Class A Common Stock necessary so that the shares
authorized for issuance under the Plan equals 12% of the number of modified
fully-diluted shares ("FDS") of Common Stock on such September 30, determined by
the following formula:

      Annual Increase = (12% - X%) x FDS,
                       Option Pool
                     ----------------   x 100
      where X% =          FDS
                                        For September 30, 2001, 24,000,000
      where the Option Pool  =          shares and for each anniversary
                                        thereafter 24,000,000 shares, plus any
                                        Annual Increases occurring prior to such
                                        anniversary.

FDS equals on each September 30 the following:
    .  the total number of shares of all classes of Common Stock outstanding;
       PLUS

    .  the total number of shares of all classes of Common Stock reserved for
       issuance in respect of outstanding:

         --  convertible securities (other than Class B and Class C Common
             Stock);

         --  options assumed or issued by the Company in connection with mergers
             and acquisitions; and

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         --  warrants; MINUS

    .  the total number of shares of all classes of Common Stock outstanding as
       a result of exercises of options granted under the Plan or any other
       employee, director or consultant options that the Company may approve,
       other than options granted under any employee stock purchase plan and
       options assumed or issued by the Company in connection with mergers or
       acquisitions; or

(ii) a lesser number than the number calculated pursuant to clause (i), as may
be determined by the Board

If the Annual Increase as calculated in clause (i) on any such September 30 is a
negative number, then no Annual Increase shall occur for that September 30.

     In the event that any outstanding Option shall expire for any reason or
shall terminate by reason of the death or severance of employment of the
Optionee, the surrender of any such Option, or any other cause, the shares of
Stock allocable to the unexercised portion of such Option may again be subject
to an option under the Plan, subject, however, in the case of ISOs to any
limitations under the Code.  The maximum number of shares of Stock subject to
Options that may be granted to any Optionee in the aggregate in any calendar
year shall not exceed 5,000,000 shares. The maximum cumulative number of shares
of stock available for grants of ISOs under the Plan is 50,000,000 shares.  All
shares references in this Section 3 shall be subject to adjustment in accordance
with the provisions of Section 17.

4.   AUTHORITY TO GRANT OPTIONS

     The Committee may determine, from time to time, which employees of the
Company or any Subsidiary or other persons shall be granted Options under the
Plan, the terms of the Options (including without limitation whether an Option
shall be an ISO or a NQO) and the number of shares which may be purchased under
the Option or Options.  Without limiting the generality of the foregoing, the
Committee may from time to time grant:  (a) to such employees (other than
employees of a Subsidiary which is not a corporation) as it shall determine an
Option or Options to buy a stated number of shares of Stock under the terms and
conditions of the Plan which Option or Options will to the extent so designated
at the time of grant constitute an ISO; and (b) to such eligible directors,
employees or other persons as it shall determine an Option or Options to buy a
stated number of shares of Stock under the terms and conditions of the Plan
which Option or Options shall constitute a NQO.  Subject only to any applicable
limitations set forth elsewhere in the Plan, the number of shares of Stock to be
covered by any Option shall be as determined by the Committee.

5.   WRITTEN AGREEMENT

     Each Option granted hereunder shall be embodied in an option agreement (the
"Option Agreement") substantially in the form of Exhibit 1, which shall be
signed by the Optionee and by the Chief Executive Officer, Chief Financial
Officer or the Corporate Controller of the Company for and in the name and on
behalf of the Company. An Option Agreement may contain such restrictions on
exercisability and such other provisions not inconsistent with the Plan as the
Committee in its sole and absolute discretion shall approve.

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6.   ELIGIBILITY

     The individuals who shall be eligible for grant of Options under the Plan
shall be employees (including officers who may be members of the Board),
directors who are not employees and other individuals, whether or not employees,
who render services of special importance to the management, operation, or
development of the Company or a Subsidiary, and who have contributed or may be
expected to contribute materially to the success of the Company or a Subsidiary.
An employee, director or other person to whom an Option has been granted
pursuant to an Option Agreement is hereinafter referred to as an "Optionee."

7.   OPTION PRICE

     The price at which shares of Stock may be purchased pursuant to an Option
shall be specified by the Committee at the time the Option is granted, but shall
in no event be less than the par value of such shares and, in the case of an
ISO, except as set forth in the following sentence, one hundred percent (100%)
of the fair market value of the Stock on the date the ISO is granted.  In the
case of an employee who owns (or is considered under Section 424(d) of the Code
as owning) stock possessing more than ten percent (10%) of the total combined
voting power of all classes of stock of the Company or any Subsidiary, the price
which shares of Stock may be so purchased pursuant to an ISO shall be not less
than one hundred and ten percent (110%) of the fair value of the Stock on the
date the ISO is granted.

     For purposes of the Plan, the "fair market value" of a share of Stock on
any date specified herein, shall mean (a) the last reported sales price, regular
way, or, in the event that no sale takes place on such day, the average of the
reported closing bid and asked prices, regular way, in either case (i) as
reported on the New York Stock Exchange Composite Tape, or (ii) if the Stock is
not listed or admitted to trading on the New York Stock Exchange, on the
principal national securities exchange on which such security is listed or
admitted to trading, or (iii) if not then listed or admitted to trading on any
national securities exchange, on the NASDAQ National Market System; or (b) if
the Stock is not quoted on such National Market System, (i) the average of the
closing bid and asked prices on each such day in the over-the-counter market as
reported by NASDAQ, or (ii) if bid and asked prices for such security on each
such day shall not have been reported through NASDAQ, the average of the bid and
asked prices for such day as furnished by any New York Stock Exchange member
firm regularly making a market in such security selected for such purpose by the
Committee; or (c) if the Stock is not then listed or admitted to trading on any
national exchange or quoted in the over-the-counter market, the fair value
thereof determined in good faith by the Committee as of a date which is within
thirty (30) days of the date with respect to which the determination is to be
made; provided, however, that any method of determining fair market value
employed by the Committee with respect to an ISO shall be consistent with any
applicable laws or regulations pertaining to "incentive stock options."

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8.   DURATION OF OPTIONS

     The duration of any Option shall be specified by the Committee in the
Option Agreement, but no ISO shall be exercisable after the expiration of ten
(10) years, and no NQO shall be exercisable after the expiration of ten (10)
years and one (1) day, from the date such Option is granted.  In the case of any
employee who owns (or is considered under Section 424(d) of the Code as owning)
stock possessing more than ten percent (10%) of the total combined voting power
of all classes of stock of the Company or any Subsidiary, no ISO shall be
exercisable after the expiration of five (5) years from the date such Option is
granted.  The Committee, in its sole and absolute discretion, may extend any
Option theretofore granted subject to the aforesaid limits and may provide that
an Option shall be exercisable during its entire duration or during any lesser
period of time.

9.   VESTING PROVISIONS

     Each Option may be exercised so long as it is valid and outstanding from
time to time, in part or as a whole, in such manner and subject to such
conditions as the Committee, in its sole and absolute discretion, may provide in
the Option Agreement.

10.  EXERCISE OF OPTIONS

     Options shall be exercised by the delivery of written notice to the Company
setting forth the number of shares of Stock with respect to which the Option is
to be exercised, accompanied by payment of the option price of such shares,
which payment shall be made, subject to the alternative provisions of this
Section, in cash or by such cash equivalents, payable to the order of the
Company in an amount in United States dollars equal to the option price of such
shares, as the Committee in its sole and absolute discretion shall consider
acceptable.  Such notice shall be delivered in person to the Secretary of the
Company or shall be sent by registered mail, return receipt requested, to the
Secretary of the Company, in which case delivery shall be deemed made on the
date such notice is deposited in the mail.

     Alternatively, if the Option Agreement so specifies, and subject to such
rules as may be established by the Committee, payment of the option price may be
made through a so-called "cashless exercise" procedure, under which the Optionee
shall deliver irrevocable instructions to a broker to sell shares of Stock
acquired upon exercise of the Option and to remit promptly to the Company a
sufficient portion of the sale proceeds to pay the option price and any tax
withholding resulting from such exercise.

     Alternatively, payment of the option price may be made, in whole or in
part, in shares of Stock owned by the Optionee; provided, however, that the
Optionee may not make payment in shares of Stock that he acquired upon the
earlier exercise of any ISO (or other "incentive stock option"), unless and
until he has held the shares until at least two (2) years after the date the ISO
(or such other incentive stock option) was granted and at least one (1) year
after the date the ISO (or such other option) was exercised.  If payment is made
in whole or in part in shares of Stock, then the Optionee shall deliver to the
Company in payment of the option price of the shares with respect of which such
Option is exercised (a) certificates registered in the name of such Optionee
representing a number of shares of Stock legally and beneficially owned by such
Optionee, free of all liens, claims and encumbrances of every kind, and having a
fair market value on the date of delivery of such notice equal to the option
price of the shares of Stock with respect to which such Option is to be
exercised, such

                                       5


certificates to be accompanied by stock powers duly endorsed in blank by the
record holder of the shares of Stock represented by such certificates; and (b)
if the option price of the shares with respect to which such Option is to be
exercised exceeds such fair market value, cash or such cash equivalents payable
to the order to the Company, in an amount in United States dollars equal to the
amount of such excess, as the Committee in its sole and absolute discretion
shall consider acceptable. Notwithstanding the foregoing provisions of this
Section, the Committee, in its sole and absolute discretion (i) may refuse to
accept shares of Stock in payment of the option price of the shares of Stock
with respect to which such Option is to be exercised and, in that event, any
certificates representing shares of Stock which were delivered to the Company
with such written notice shall be returned to such Optionee together with notice
by the Company to such Optionee of the refusal of the Committee to accept such
shares of Stock and (ii) may accept, in lieu of actual delivery of stock
certificates, an attestation by the Optionee substantially in the form attached
herewith as Exhibit C or such other form as may be deemed acceptable by the
Committee that he or she owns of record the shares to be tendered free and clear
of all liens, claims and encumbrances of every kind.

     Alternatively, if the Option Agreement so specifies, payment of the option
price may be made in part by a promissory note executed by the Optionee and
containing the following terms and conditions (and such others as the Committee
shall, in its sole and absolute discretion determine from time to time):  (a) it
shall be collaterally secured by the shares of Stock obtained upon exercise of
the Option; (b) repayment shall be made on demand by the Company and, in any
event, no later than three (3) years from the date of exercise; and (c) the note
shall bear interest at a rate as determined by the Committee, payable monthly
out of a payroll deduction provision; provided, however, that notwithstanding
the foregoing (i) an amount not less than the par value of the shares of Stock
with respect to which the Option is being exercised must be paid in cash, cash
equivalents, or shares of Stock in accordance with this Section, and (ii) the
payment of such exercise price by promissory note does not violate any
applicable laws or regulations, including, without limitation, Delaware
corporate law or applicable margin lending rules.  The decision as to whether to
permit partial payment by a promissory note for shares of Stock to be issued
upon exercise of any Option granted shall rest entirely in the sole and absolute
discretion of the Committee.

     As promptly as practicable after the receipt by the Company of (a) written
notice from the Optionee setting forth the number of shares of Stock with
respect to which such Option is to be exercised and (b) payment of the option
price of such shares in the form required by the foregoing provisions of this
Section, the Company shall cause to be delivered to such Optionee certificates
representing the number of shares with respect to which such Option has been so
exercised (less a number of shares equal to the number of shares as to which
ownership was attested under the procedure described in clause (ii) of the next
preceding paragraph).

11.  TRANSFERABILITY OF OPTIONS

     Options shall not be transferable by the Optionee otherwise than by will or
under the laws of descent and distribution, and shall be exercisable during his
or her lifetime only by the Optionee, except that the Committee may specify in
an Option Agreement that pertains to an NQO that the Optionee may transfer such
NQO to a member of the Immediate Family of the Optionee, to a trust solely for
the benefit of the Optionee and the Optionee's Immediate

                                       6


Family, or to a partnership or limited liability company whose only partners or
members are the Optionee and members of the Optionee's Immediate Family.
"Immediate Family" shall mean, with respect to any Optionee, such Optionee's
child, stepchild, grandchild, parent, stepparent, grandparent, spouse, sibling,
mother-in-law, father-in-law, son-in-law, daughter-in-law, brother-in-law, or
sister-in-law, and shall include adoptive relationships.

12.  TERMINATION OF EMPLOYMENT OR INVOLVEMENT OF OPTIONEE WITH THE COMPANY

     For purposes of this Section, employment by or involvement with (in the
case of an Optionee who is not an employee) a Subsidiary shall be considered
employment by or involvement with the Company.  Except as otherwise set forth in
the Option Agreement, after the Optionee's termination of employment with the
Company other than by reason of death or disability, including his retirement in
good standing from the employ of the Company for reasons of age under the then
established rules of the Company, the Option shall terminate on the earlier of
the date of its expiration or three (3) months after the date of such
termination or retirement.  After the death of the Optionee, his or her
executors, administrators or any persons to whom his or her Option may be
transferred by will or by the laws of descent and distribution shall have the
right to exercise the Option to the extent to which the Optionee was entitled to
exercise the Option.  In the event that such termination is a result of
disability, the Optionee shall have the right to exercise the Option pursuant to
its terms as if such Optionee continued as an employee.

     Authorized leave of absence or absence on military or government service
shall not constitute severance of the employment relationship between the
Company and the Optionee for purposes of the Plan, provided that either (a) such
absence is for a period of no more than ninety (90) days or (b) the Employee's
right to re-employment after such absence is guaranteed either by statute or by
contract.

     For Optionees who are not employees of the Company, options shall be
exercisable for such periods following the termination of the Optionee's
involvement with the Company as may be set forth in the Option Agreement.

13.  REQUIREMENTS OF LAW

     The Company shall not be required to sell or issue any shares of Stock upon
the exercise of any Option if the issuance of such shares shall constitute or
result in a violation by the Optionee or the Company of any provisions of any
law, statute or regulation of any governmental authority. Specifically, in
connection with the Securities Act of 1933, as amended (the "Securities Act"),
and any applicable state securities or "blue sky" law (a "Blue Sky Law"), upon
exercise of any Option the Company shall not be required to issue such shares
unless the Committee has received evidence satisfactory to it to the effect that
the holder of such Option will not transfer such shares except pursuant to a
registration statement in effect under the Securities Act and Blue Sky Laws or
unless an opinion of counsel satisfactory to the Company has been received by
the Company to the effect that such registration and compliance is not required.
Any determination in this connection by the Committee shall be final, binding
and conclusive.  The Company shall not be obligated to take any action in order
to cause the exercise of an Option or the issuance of shares of Stock

                                       7


pursuant thereto to comply with any law or regulations of any governmental
authority, including, without limitation, the Securities Act or applicable Blue
Sky Law.

     Notwithstanding any other provision of the Plan to the contrary, the
Company may refuse to permit transfer of shares of Stock if in the opinion of
its legal counsel such transfer would violate federal or state securities laws
or subject the Company to liability thereunder.  Any sale, assignment, transfer,
pledge or other disposition of shares of Stock received upon exercise of any
Option (or any other shares or securities derived therefrom) which is not in
accordance with the provisions of this Section shall be void and of no effect
and shall not be recognized by the Company.

     Legend on Certificates.  The Committee may cause any certificate
representing shares of Stock acquired upon exercise of an Option (and any other
shares or securities derived therefrom) to bear a legend to the effect that the
securities represented by such certificate have not been registered under the
Federal Securities Act of 1933, as amended, or any applicable state securities
laws, and may not be sold, assigned, transferred, pledged or otherwise disposed
of except in accordance with the Plan and applicable agreements binding the
holder and the Company or any of its stockholders.

14.  NO RIGHTS AS STOCKHOLDER

     No Optionee shall have any rights as a stockholder with respect to shares
covered by his or her Option until the date of issuance of a stock certificate
for such shares; except as otherwise provided in Section 17, no adjustment for
dividends or otherwise shall be made if the record date therefor is prior to the
date of issuance of such certificate.

15.  EMPLOYMENT OBLIGATION

     The granting of any Option shall not impose upon the Company or any
Subsidiary any obligation to employ or continue to employ any Optionee, or to
engage or retain the services of any person, and the right of the Company or any
Subsidiary to terminate the employment or services of any person shall not be
diminished or affected by reason of the fact that an Option has been granted to
him or her.  The existence of any Option shall not be taken into account in
determining any damages relating to termination of employment or services for
any reason.

16.  FORFEITURE AS A RESULT OF TERMINATION FOR CAUSE

     Notwithstanding any provision of the Plan to the contrary, if the Committee
determines, after full consideration of the facts presented on behalf of the
Company and an Optionee, that

     (a) the Optionee has been engaged in fraud, embezzlement, theft, commission
of a felony or dishonesty in the course of his or her employment by or
involvement with the Company or a Subsidiary, which damaged the Company or a
Subsidiary, or has made unauthorized disclosure of trade secrets or other
proprietary information of the Company or a Subsidiary or of a third party who
has entrusted such information to the Company or a Subsidiary, or

                                       8


     (b) the Optionee's employment or involvement was otherwise terminated for
"cause," as defined in any employment agreement with the Optionee, if
applicable, or if there is no such agreement, as determined by the Committee,
which may determine that "cause" includes among other matters the willful
failure or refusal of the Optionee to perform and carry out his or her assigned
duties and responsibilities diligently and in a manner satisfactory to the
Committee, then the Optionee's right to exercise an Option shall terminate as of
the date of such act (in the case of (a)) or such termination (in the case of
(b)) and the Optionee shall forfeit all unexercised Options. If an Optionee
whose behavior the Company asserts falls within the provisions of (a) or (b)
above has exercised or attempts to exercise an Option prior to a decision of the
Committee, the Company shall not be required to recognize such exercise until
the Committee has made its decision and, in the event of any exercise shall have
taken place, it shall be of no force and effect (and void ab initio) if the
Committee makes an adverse determination; provided, however, if the Committee
finds in favor of the Optionee then the Optionee will be deemed to have
exercised such Option retroactively as of the date he or she originally gave
written notice of his or her attempt to exercise or actual exercise, as the case
may be.  The decision of the Committee as to the cause of an Optionee's
discharge and the damage done to the Company or a Subsidiary shall be final,
binding and conclusive.  No decision of the Committee, however, shall affect in
any manner the finality of the discharge of such Optionee by the Company or a
Subsidiary.

17.  CHANGES IN THE COMPANY'S CAPITAL STRUCTURE

     The existence of outstanding Options shall not affect in any way the right
or power of the Company or its stockholders to make or authorize any or all
adjustments, recapitalizations, reorganizations or other changes in the
Company's capital structure or its business or any merger or consolidation of
the Company or any issue of bonds, debentures, preferred or preference stock,
whether or not convertible into the Stock or other securities, ranking prior to
the Stock or affecting the rights thereof, or warrants, rights or options to
acquire the same, or the dissolution or liquidation of the Company or any sale
or transfer of all or any part of its assets or business or any other corporate
act or proceeding, whether of a similar character or otherwise.

     The number of shares of Stock in the Option Pool (less the number of shares
theretofore delivered upon exercise of Options) and the number of shares of
Stock covered by any outstanding Option and the price per share payable upon
exercise thereof (provided that in no event shall the option price be less than
the par value of such shares) shall be proportionately adjusted for any increase
or decrease in the number of issued and outstanding shares of Stock resulting
from any subdivision, split, combination or consolidation of shares of Stock or
the payment of a dividend in shares of stock or other securities of the Company
on the Stock.  The decision of the Board as to the adjustment, if any, required
by the provisions of this Section shall be final, binding and conclusive.

     If the Company merges or consolidates with a wholly-owned subsidiary for
the purpose of reincorporating itself under the laws of another jurisdiction,
the Optionees will be entitled to acquire shares of Stock of the reincorporated
Company upon the same terms and conditions as were in effect immediately prior
to such reincorporation (unless such reincorporation involves a change in the
number of shares or the capitalization of the Company, in which case
proportional adjustments shall be made as provided above) and the

                                       9


Plan, unless otherwise rescinded by the Board, will remain the Plan of the
reincorporated Company.

     Except as otherwise provided in the preceding paragraph, if the Company is
merged or consolidated with another corporation, whether or not the Company is
the surviving entity, or if the Company is liquidated or sells or otherwise
disposes of all or substantially all of its assets to another entity while
unexercised Options remain outstanding under the Plan, or if other circumstances
occur in which the Board in its sole and absolute discretion deems it
appropriate for the provisions of this paragraph to apply (in each case, an
"Applicable Event"), then (a) each holder of an outstanding Option shall be
entitled, upon exercise of such Option, to receive in lieu of shares of Stock,
such stock or other securities or property as he or she would have received had
he exercised such option immediately prior to the Applicable Event; or (b) the
Board may, in its sole and absolute discretion, waive, generally or in one or
more specific cases, any limitations imposed pursuant to Section 9 so that some
or all Options from and after a date prior to the effective date of such
Applicable Event, specified by the Board, in its sole and absolute discretion,
shall be exercisable in full; or (c) the Board may, in its sole and absolute
discretion, cancel all outstanding and unexercised Options as of the effective
date of any such Applicable Event; or (d) the Board may, in its sole discretion,
convert some or all Options into options to purchase the stock or other
securities of the surviving corporation pursuant to an Applicable Event; or (e)
the Board may, in its sole and absolute discretion, assume the outstanding and
unexercised options to purchase stock or other securities of any corporation and
convert such options into Options to purchase Stock, whether pursuant to this
Plan or not, pursuant to an Applicable Event; provided, however, notice of any
such cancellation pursuant to clause (c) shall be given to each holder of an
Option not less than thirty (30) days preceding the effective date of such
Applicable Event,  and provided further, however, that the Board may, in its
sole and absolute discretion, waive, generally or in one or more specific
instances, any limitations imposed pursuant to Section 9 with respect to any
Option so that such Option shall be exercisable in full or in part, as the Board
may, in its sole and absolute discretion, determine, during such thirty (30) day
period.

     Except as expressly provided herein, the issue by the Company of shares of
Stock or other securities of any class or series or securities convertible into
or exchangeable or exercisable for shares of Stock or other securities of any
class or series for cash or property or for labor or services either upon direct
sale or upon the exercise of rights or warrants to subscribe therefor, or upon
conversion of shares or obligations of the Company convertible into such shares
or other securities, shall not affect, and no adjustment by reason thereof shall
be made with respect to, the number, class or price of shares of Stock then
subject to outstanding Options.

18.  AMENDMENT OR TERMINATION OF PLAN

     The Board may, in its sole and absolute discretion, modify, revise or
terminate the Plan at any time and from time to time; provided, however, that
without the further approval of the holders of at least a majority of the
outstanding shares of Stock, the Board may not (a) materially increase the
benefits accruing to Optionees under the Plan or make any "modifications" as
that term is defined under Section 424(h)(3) (or its successor) of the Code if
such increase in benefits or modifications would adversely affect (i) the
availability to the Plan of the protections of Section 16(b) of the Exchange
Act, if applicable to the Company,

                                       10


or (ii) the qualification of the Plan or any Options for "incentive stock
option" treatment under Section 422 of the Code; (b) change the aggregate number
of shares of Stock which may be issued under Options pursuant to the provisions
if the Plan either to any one employee or in the aggregate; or (c) change the
class of persons eligible to receive ISOs. Notwithstanding the preceding
sentence, the Board shall in all events have the power and authority to make
such changes in the Plan and in the regulations and administrative provisions
hereunder or in any outstanding Option as, in the opinion of counsel for the
Company, may be necessary or appropriate from time to time to enable any Option
granted pursuant to the Plan to qualify as an incentive stock option or such
other stock option as may be defined under the Code, as amended from time to
time, so as to receive preferential federal income tax treatment.

19.  EFFECTIVE DATE AND DURATION OF THE PLAN

     The Plan shall become effective and shall be deemed to have been adopted on
November 5, 1997, unless the Plan shall have terminated earlier, the Plan shall
terminate on the tenth (10th) anniversary of its effective date, and no Option
shall be granted pursuant to the Plan after the day preceding the tenth (10th)
anniversary of its effective date.

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