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                                                                   Exhibit 10.21

                              PHARMACIA CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN

         SECTION 1.  PURPOSE. The Plan is designed to encourage employee stock
ownership in the Company by providing Employees of the Company and Eligible
Subsidiaries with an opportunity to purchase Common Stock through voluntary
systematic payroll deductions. It is the purpose and policy of the Plan to
foster ownership interest among Employees, thus aligning the interests of
Employees with the interests of stockholders. The Company intends that the Plan
qualify as an "Employee Stock Purchase Plan" under Section 423 of the Internal
Revenue Code of 1986, as amended and the Plan shall be construed in accordance
with such intent.

         SECTION 2.  DEFINITIONS.  The following terms, when used in the Plan,
shall have the following meanings:

         a.   "Administrator" means the Compensation Committee of the Board and
              any individual or individuals (including without limitation,
              another subcommittee of the Board) to whom the Compensation
              Committee has delegated any or all of its administrative powers
              and duties under the Plan.

         b.   "Board" means the Board of Directors of the Company.

         c.   "Business Day" means mean a day on which the New York Stock
              Exchange is open for trading.

         d.   "Common Stock" means the common stock of the Company.

         e.   "Company" means Pharmacia Corporation.

         f.   "Compensation" means annualized base salary paid by the Company or
              an Eligible Subsidiary.

         g.   "Eligible Subsidiary" means a Subsidiary that has been designated
              by the Administrator to participate in an Offering.

         h.   "Employee" means any individual who is treated on the Enrollment
              Date as an employee of the Company or an Eligible Subsidiary for
              tax purposes.

         i.   "Enrollment Date" means the first Business Day of an Offering
              Period.

         j.   "Enrollment Form" means a subscription agreement for an Offering,
              on a form prescribed by the Administrator, authorizing the Company
              to make payroll deductions for purposes of the Plan and
              designating the beneficiary who will receive payments due to the
              participant in the event of the participant's death.

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         k.   "Enrollment Period" means the period prior to the Enrollment Date
              during which Employees may enroll in an Offering.

         l.   "Offering" means the grant of an option to purchase Common Stock
              under the Plan, as described in Section 6(a).

         m.   "Offering Period" means the period during which an option granted
              pursuant to an Offering may be exercised via voluntary payroll
              deductions.

         n.   "Plan" means this Pharmacia Corporation Employee Stock Purchase
              Plan, as may be amended from time to time.

         o.   "Purchase Date" means the date or dates that Common Stock is
              purchased under an Offering, which date(s) shall be the last
              Business Day of each Purchase Period.

         p.   "Purchase Period" means the period between Purchase Dates, except
              that the first Purchase Period of any Offering Period shall be the
              period between the Enrollment Date and the first Purchase Date of
              the Offering Period.

         q.   "Purchase Price" means the purchase price per share of Common
              Stock under an Offering, as fixed by the Administrator in
              accordance with Section 6(e) of the Plan.

         r.   "Subsidiary" means a corporation (other than the Company), whether
              domestic or foreign, in an unbroken chain of corporations
              beginning with the Company, of which not less than 50% of the
              total combined voting power of all classes of stock in such
              corporation is held by the Company or another corporation (other
              than the last corporation) in such chain. For purposes of
              determining which entities are Subsidiaries, a partnership that
              has elected to be taxed as a corporation shall be treated as a
              corporation during the period for which such election applies.

         SECTION 3. COMMON STOCK SUBJECT TO THE PLAN. The shares that may be
offered under the Plan shall be issued and outstanding shares of Common Stock
that are acquired by the Company from time to time in open market transactions.
The number of shares of Common Stock that may be purchased by participants under
the Plan may not exceed 70,000,000 shares, except as such number may be adjusted
pursuant to Section 11. All shares offered under the Plan that are not
purchased, and any previously unoffered shares, will be available for subsequent
Offerings.

         SECTION 4. ADMINISTRATION OF THE PLAN. The Plan shall be administered
by the Administrator. The Administrator shall serve at the pleasure of the Board
and shall have such powers, duties and discretions as set out in the Plan and as
the Board may from time to time confer upon it. The Administrator shall have
sole and absolute discretion to interpret the Plan, to make determinations as to
the eligibility of Employees to participate in the Plan and to adopt rules and
regulations for administering the Plan. Any decision or action by the Board or
the Administrator arising out of or in connection with the construction,
administration, interpretation

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and effect of the Plan shall be conclusive and binding upon all Employees
participating in the Plan and any person claiming under or through any such
Employee.

         SECTION 5.  ELIGIBILITY.  Only eligible Employees of the Company or an
Eligible Subsidiary may participate in an Offering.

         a.   Eligible Subsidiaries. Prior to the commencement of the Enrollment
              Period, the Administrator shall designate the Subsidiaries that
              shall be the Eligible Subsidiaries for the Offering.

         b.   Eligible Employees. All Employees of the Company or any Eligible
              Subsidiary shall be eligible to participate in an Offering;
              except, however, that the Administrator may, in its discretion and
              on a uniform basis, exclude from any Offering or Offerings
              Employees who, as of the Enrollment Date for the Offering:

              (i)   Have not completed a minimum period of employment that may
                    be fixed from time to time by the Administrator, in its
                    discretion and on a uniform basis; provided, however, that
                    in no event may such minimum employment period exceed
                    twenty-four (24) months in length;

              (ii)  Are customarily employed for less than twenty (20) hours per
                    week;

              (iii) Are customarily employed for not more than five (5) months
                    in any calendar year; or

              (iv)  Are "highly compensated employees," within the meaning of
                    Section 414(q) of the Internal Revenue Code of 1986, as
                    amended.

              All Employees participating in an Offering shall have the same
              rights and privileges to purchase Common Stock under the Plan;
              except that the amount of Common Stock that may be purchased by
              any Employee under an Offering may bear a uniform relationship to
              the total Compensation of Employees.

         c.   Limitations on Participation. Notwithstanding the foregoing, no
              Employee shall be eligible to participate in an Offering to the
              extent that:

              (i)    Such Employee owns, or would own immediately after such
                     Offering, stock possessing five percent (5%) or more of the
                     combined voting power or value of all classes of stock of
                     the Company or any Subsidiary; or

              (ii)   Such Employee's rights to purchase stock under all employee
                     stock purchase plans (within the meaning of Section 423 of
                     the Code) of the Company and its Subsidiaries accrues at a
                     rate that exceeds $25,000 worth of stock (determined at the
                     fair market value of the shares at the time such rights are
                     granted) for each calendar year during which the rights to
                     purchase such stock are outstanding at any time.

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         SECTION 6. OFFERINGS UNDER THE PLAN. The terms and conditions of each
Offering shall be determined by the Administrator prior to the commencement of
the Enrollment Period for the Offering in accordance with this Section 6.

         a.   Grant and Exercise of Options. On the Enrollment Date of each
              Offering, each eligible Employee shall be granted an option to
              purchase during the Offering Period (at the applicable Purchase
              Price) up to the number of shares of Common Stock determined by
              dividing such Employee's payroll deductions accumulated during
              each Purchase Period in the Offering Period by the applicable
              Purchase Price. Unless a participant withdraws from the Offering
              in accordance with Section 8(c) prior to the Purchase Date, the
              option will be automatically exercised on each Purchase Date with
              respect to the number of shares subject to the option that can be
              purchased with payroll deductions accumulated during the
              applicable Purchase Period in accordance with Section 9.

         b.   Enrollment Date. The Enrollment Date for each Offering shall be
              fixed by the Administrator prior to the announcement of the
              Offering.

         c.   Offering Period. Unless the Administrator, in its discretion,
              determines that a different Offering Period shall apply to an
              Offering, the Offering Period shall be the twenty-four (24) month
              period commencing on the Enrollment Date. In no event shall any
              Offering Period under the Plan exceed twenty-seven (27) months.
              Offering Periods under the Plan may overlap.

         d.   Purchase Periods. Each Offering Period shall consist of one or
              more Purchase Periods. Unless the Administrator, in its
              discretion, determines otherwise with respect to an Offering, each
              24-month Offering Period shall be divided into four 6-month
              Purchase Periods.

         e.   Purchase Price. The per share Purchase Price of the Common Stock
              available for purchase under an Offering shall be fixed by the
              Administrator prior to the Enrollment Date. In no event shall the
              Purchase Price applicable to an Offering be fixed at a price lower
              than the lesser of:

              (i)    85% of the fair market value of a share of Common Stock on
                     the Enrollment Date; and

              (ii)   85% of the fair market value of a share of Common Stock on
                     the applicable Purchase Date.

              The Purchase Price fixed for an Offering shall be subject to
              adjustment pursuant to Section 11 of the Plan.

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         SECTION 7.  ENROLLMENT AND PARTICIPATION.

         a.   Enrollment. An eligible Employee shall become a participant in an
              Offering by filing a properly completed Enrollment Form with the
              designated Plan representative before the end of the applicable
              Enrollment Period.

         b.   Enrollment Period. Unless the Administrator determines otherwise
              with respect to an Offering, the Enrollment Period for each
              Offering shall be the forty-five (45) day period commencing sixty
              (60) days prior to the Enrollment Date of the Offering. Although
              the Administrator may, in its discretion, determine that a longer
              or shorter Enrollment Period may apply to an Offering, in no event
              shall any Enrollment Period extend past a date that is less than
              fifteen (15) days prior to the Enrollment Date of the Offering.

         SECTION 8.  PAYROLL DEDUCTION ELECTIONS, WITHDRAWAL RIGHTS, BENEFICIARY
DESIGNATIONS.

         a.   Deduction Election. An eligible Employee who desires to
              participate in an Offering shall elect on the Enrollment Form to a
              have a portion of his or her Compensation, not exceeding in the
              aggregate $25,000 for any calendar year, deducted from his or her
              pay for each pay period during the Offering Period. At the
              discretion of the Administrator, the Enrollment Form may provide
              that the portion of Compensation deducted be expressed as either
              (i) a percentage of Compensation only, (ii) a flat dollar amount
              only or (iii) either a percentage of Compensation or a flat dollar
              amount, as elected by the participant. All amounts deducted from a
              participant's pay shall be credited to a recordkeeping account
              established under the Plan on behalf of the participant for the
              Offering. Payroll deductions shall commence on the first pay
              period after the Enrollment Date and shall continue until the last
              pay period in the Offering Period, unless deductions are suspended
              by the participant as provided in Section 8(b) or the participant
              withdraws from the Offering as provided in Section 8(c).

         b.   Change in Elections. The Committee may, in its discretion, permit
              participants in an Offering to increase (subject to the maximum
              annual dollar limitation) or decrease the percentage of
              Compensation deducted from pay, or suspend payroll deductions
              entirely, by completing and filing with the designated Plan
              representative a new Enrollment Form authorizing a change in
              payroll deduction rate. The Committee may, in its discretion,
              limit the number of deduction rate changes that participants may
              make during an Offering Period and may designate specific times
              during an Offering Period when such rate changes may be made. At
              the discretion of the Committee, a participant who suspends
              payroll deductions, but does not withdraw from the Offering, may
              be permitted to reinstate payroll deductions by completing and
              filing a new Enrollment Form. Any change in deduction rate or
              suspension of deductions made pursuant to this Section 4(c) shall
              have prospective effect only. Any determination of the

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              Committee to permit changes in the deduction rates elected by
              participants shall apply to all participants on a uniform basis.

         c.   Withdrawal From Offering. Each participant in an Offering shall
              have the absolute right to withdraw from the Offering at any time
              during the Offering Period by completing and filing with the
              designated Plan representative a withdrawal notice on a form
              prescribed by the Administrator. In the event that a participant
              withdraws from an Offering, all payroll deductions shall cease and
              any amounts credited to the participant's recordkeeping account
              that have not already been applied to the purchase of Common Stock
              shall be returned to the participant in cash, without interest, as
              soon as practicable after receipt of the withdrawal notice. A
              participant who withdraws from an Offering shall not be permitted
              to participate again in such Offering, but may be permitted to
              participate in any subsequent Offerings under the Plan.

         d.   Termination of Employment or Death. Upon a participant's
              termination of employment for any reason (including death) during
              an Offering Period, the participant shall be deemed to have
              elected to withdraw from the Offering in accordance with Section
              8(c) and the payroll deductions credited to such participant's
              account during the Offering Period, but not yet used to purchase
              Common Stock, shall be returned to the participant, without
              interest, or in the case of the participant's death, to the
              participant's beneficiary designated in accordance with Section
              8(e). Notwithstanding the foregoing, in the event of a termination
              of employment that occurs within thirty (30) days prior to a
              Purchase Date, the Committee may (in its discretion, but on a
              uniform basis) treat the termination of employment as an election
              to suspend deductions under Section 8(b) and the payroll
              deductions credited to the participant's account as of the date of
              employment termination will be used to purchase Common Stock on
              the Purchase Date in accordance with Section 9. In such case, if
              the termination of employment was due to the participant's death,
              any Common Stock purchased under this Section 8(d) shall be issued
              and delivered to the beneficiary designated by the participant
              under Section 8(e).

         e.   Designation of Beneficiary. A participant may designate on the
              Enrollment Form a beneficiary who is to receive any cash or shares
              of Common Stock from the participant's account in the event of the
              participant's death. Such designation may be changed by the
              participant at any time by filing a new Enrollment Form. In the
              event that a valid beneficiary designation is not on file at the
              time of a participant's death, or if the participant's designated
              beneficiary predeceases the participant, the participant's
              designated beneficiary shall be deemed to be the participant's
              estate.

         SECTION 9. PURCHASE AND DELIVERY OF COMMON STOCK. On each Purchase Date
during an Offering Period, the payroll deductions that have accumulated in a
participant's account during the applicable Purchase Period shall automatically
be applied toward the purchase of Common Stock on behalf of the participant in
accordance with this Section 9.

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         a.   Number of Shares Purchased. The number of whole shares of Common
              Stock that will be purchased on behalf of a participant on any
              given Purchase Date shall be determined by dividing the amount of
              such participant's accumulated payroll deductions that have been
              credited to the participant's account during the applicable
              Purchase Period by the applicable Purchase Price. No fractional
              shares shall be purchased; any payroll deductions credited to a
              participant's account that are not sufficient to purchase a full
              share of Common Stock shall be retained in the account and applied
              to the subsequent Purchase Period. If there is no subsequent
              Purchase Period, amounts remaining in a participant's account
              after the Purchase Date shall be returned to the participant,
              without interest.

         b.   Issuance of Shares. Unless otherwise requested by a participant,
              shares purchased under the Plan shall be issued and held on behalf
              of a participant in street name by a nationally recognized
              securities firm chosen by the Administrator.

         c.   Conditions Upon Issuance of Shares. No shares shall be issued
              under the Plan unless the purchase of such shares and the delivery
              and issuance of the shares complies with all applicable provisions
              of law, domestic or foreign, including without limitation, the
              Securities Act of 1933, as amended, the Securities Exchange Act of
              1934, as amended, the rules and regulations promulgated
              thereunder, and the requirements of any stock exchange upon which
              the shares may be listed, and shall be further subject to the
              approval of counsel to the Company with respect to such
              compliance.

         d.   Stockholder Rights. No participant shall have any rights as a
              stockholder with respect to shares of Common Stock unless and
              until such shares are issued on behalf of the participant in
              accordance with this Section 9.

         SECTION 10. TRANSFERABILITY. The rights of a participant under the Plan
shall not be transferable by the participant other than by will, the laws of
descent and distribution or to a participant's designated beneficiary as
provided in Section 8(e). Any attempt at transfer will be without effect, except
that the Committee may treat any such attempted transfer as an election to
withdraw from an Offering under Section 8(c).

         SECTION 11. ADJUSTMENT OF SHARES AND PURCHASE PRICE. If at any time the
Company takes any action, whether by stock dividend, stock spilt, combination of
shares or otherwise, which results in a proportionate increase or decrease in
the number of shares of Common Stock theretofore issued and outstanding, then
(i) the number of shares subject to the Plan shall be increased or decreased
proportionately, (ii) the Purchase Price fixed by the Administrator pursuant to
Section 6(e) shall be adjusted accordingly and (iii) such other adjustments may
be made that the Administrator deems equitable.

         SECTION 12. AMENDMENT AND DISCONTINUANCE. The Compensation Committee of
the Board may amend or discontinue the Plan at any time. No such amendment,
however, may increase the maximum number of shares that may be offered under the
Plan, decrease the

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minimum Purchase Price under Section 6(e) or change the class of eligible
Employees under the Plan (other than to designate additional Eligible
Subsidiaries) without the approval of a majority of the holders of Common Stock.

         SECTION 13. EFFECTIVE DATE; SHAREHOLDER APPROVAL. The Plan shall become
effective as of January 1, 2002 or such later date as the Administrator may
determine, subject to the approval of a majority of the holders of the shares of
Common Stock present and represented at any special or annual meeting of the
Company's shareholders duly held within twelve (12) months after adoption of the
Plan. If the Plan is not so approved, the Plan shall not become effective.

         SECTION 14. NO EMPLOYMENT RIGHTS. The Plan does not, directly or
indirectly, create in any person any right with respect to continuation of
employment by the Company or any Subsidiary, and it shall not be deemed to
interfere in any way with the right of the Company or any Subsidiary to
terminate, or otherwise modify, any Employee's employment at any time.

         SECTION 15. GOVERNING LAWS.  The laws of the State of Delaware shall
govern all matters relating to the Plan, except to the extent such laws are
superceded by the federal laws of the United States.

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                                                                       EXHIBIT B

                              AMENDMENT NO. 2001-1
                                     TO THE

                              PHARMACIA CORPORATION
                          2001 LONG-TERM INCENTIVE PLAN

        WHEREAS, the Compensation Committee of the Board of Directors of
Pharmacia Corporation (the "Committee") adopted the Pharmacia Corporation 2001
Long-Term Incentive Plan (the "Plan") subject to shareholder approval,
substantially in the form presented to the Committee at its meeting on December
7, 2000;

        WHEREAS, the plan was approved by the Company's shareholders at the
Company's annual meeting held on April 17, 2001, in the form attached hereto as
Exhibit A, with a commitment from the Company to amend the Plan to prohibit the
repricing, replacement or regranting through cancellation or by lowering the
option exercise price, of any options granted under the Plan without prior
shareholder approval;

        WHEREAS, the Committee authorized the Senior Vice President Human
Resources to approve the specific terms of the Plan and to take all other
actions and execute all documents necessary to effectuate the adoption of the
Plan;

        NOW, THEREFORE, effective April 18, 2001, the Plan is hereby amended by
adding the following sentence to the end of paragraph 1 (b):

             "Notwithstanding anything herein to the contrary, no grant issued
             under the Plan shall permit the repricing, replacement or
             regranting through cancellation or by lowering the Option exercise
             price, of any Option granted under the Plan without prior
             shareholder approval."

        The Plan is further hereby amended by adding the following sentence to
the end of paragraph 16(a):

             "Notwithstanding anything herein to the contrary, neither
             the Plan, nor the terms of any previously issued grant
             under the Plan, may be amended to permit the repricing,
             replacement or regranting through cancellation or by
             lowering the Option exercise price, of any Option granted
             under the Plan without prior shareholder approval."

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