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                                                                   EXHIBIT 10.46

                                SECOND AMENDMENT
                                     TO THE
                 WATERS CORPORATION SECOND AMENDED AND RESTATED
                    1996 LONG-TERM PERFORMANCE INCENTIVE PLAN

      WHEREAS, Waters Corporation (the "Corporation") has established and
maintains an incentive plan for the benefit of certain key employees of the
Corporation and its subsidiaries entitled the Waters Corporation Second Amended
and Restated 1996 Long-Term Performance Incentive Plan (the "Plan"); and

      WHEREAS, the Corporation desires to amend the Plan;

      NOW THEREFORE, in accordance with the power of amendment contained in
Section 17 of the Plan, the Plan is hereby amended, effective as of December 13,
2006, as follows:

      1.    The first paragraph of Section 13 of the Plan ("Dilution and Other
            Adjustments") is hereby amended to read in its entirety as follows:

                  "In the event of any change in the outstanding Common Shares
                  of the Company by reason of any stock split, dividend,
                  split-up, split-off, spin-off, recapitalization, merger,
                  consolidation, rights offering, reorganization, combination or
                  exchange of shares, a sale by the Company of all of its
                  assets, any distribution to stockholders other than a normal
                  cash dividend, or other extraordinary or unusual event, in
                  each such case occurring after June 10, 1999, an appropriate
                  and proportionate adjustment will be made in (i) the maximum
                  numbers and kinds of shares subject to the Plan, (ii) the
                  numbers and kinds of shares or other securities subject to the
                  then outstanding Awards, (iii) the exercise or hurdle price
                  for each share or other unit of any other securities subject
                  to then outstanding Options or Stock Appreciation Rights
                  (without change in the aggregate purchase price as to which
                  such Options or Stock Appreciation Rights remain exercisable),
                  and (iv) the repurchase price of each share of Restricted
                  Stock then subject to a Restricted Period by reason of a
                  Company repurchase right. Any adjustment in Awards made
                  pursuant to this Section 13 shall be determined and made by
                  the Committee and shall include any correlative modification
                  of terms, including of Option or Stock Appreciation Right
                  exercise or hurdle prices, rates of vesting or exercisability,
                  Restricted Periods and applicable repurchase prices for
                  Restricted

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                  Stock, which the Committee may deem necessary or appropriate
                  so as to ensure the rights of the participants in their
                  respective Awards are not substantially diminished or enlarged
                  as a result of the adjustment and corporate action other than
                  as expressly contemplated in this Section 13. No fraction of a
                  share shall be purchasable or deliverable upon exercise, but
                  in the event any adjustment hereunder of the number of shares
                  covered by an Award shall cause such number to include a
                  fraction of a share, such number of shares shall be adjusted
                  to the nearest smaller whole number of shares. No adjustment
                  of an Option exercise price or Stock Appreciation Right hurdle
                  price per share pursuant to this Section 13 shall result in an
                  exercise price or hurdle price which is less than the par
                  value of the Common Shares."

      IN WITNESS WHEREOF, the Board of Directors of the Corporation has caused
this amendment to be signed on its behalf by its duly authorized representative
this 13th day of December, 2006.

                                 WATERS CORPORATION

                                 By:  /s/ Elizabeth B. Rae
                                      ---------------------------------------

                                 Its: Vice President, Corporate Human Resources