<PAGE>
                                                                    Exhibit 10.1



                              TAX SHARING AGREEMENT

                                       BY

                                 SPX CORPORATION

                                       AND

                        INRANGE TECHNOLOGIES CORPORATION


<PAGE>



                                TABLE OF CONTENTS



<TABLE>
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                                                                               PAGE
                                                                               ----

<S>                                                                           <C>
SECTION 1. Definition of Terms ............................................      1

SECTION 2. Allocation of Income Tax Liabilities ...........................      6

   2.1.  Federal Income Tax ...............................................      6
   2.2.  Other Income Taxes ...............................................      7
   2.3.  Calculation of Income Tax Liability ..............................      7
   2.4.  Income Taxes from the Distribution ...............................      8
   2.5.  Income Tax Payments and Intercompany Billings ....................      9

SECTION 3.  Preparation and Filing of Tax Returns .........................      9

   3.1.  General ..........................................................      9
   3.2.  Pre-Deconsolidation Period and Straddle Period Tax Returns .......      9
   3.3.  Post-Deconsolidation Period Tax Returns ..........................     10
   3.4.  Tax Accounting Practices .........................................     10
   3.5.  Right to Review Tax Returns ......................................     11

SECTION 4.  Refunds, Carrybacks and Tax Benefits ..........................     11

   4.1.  Compensation for Use of INRANGE Consolidated Period Tax Items ....     11
   4.2.  Claims for Refund, Carrybacks, and Self-Audit Adjustments ........     12
   4.3.  Adjustment  of Tax Items .........................................     14
   4.4.  Adjustments on Audit .............................................     14

SECTION 5.  Tax Payments and Intercompany Billings ........................     15

   5.1.  Payment of Income Taxes With Respect to SPX Consolidated Returns..     15
   5.2.  Payment of Income Tax Related to Adjustments .....................     16
   5.3.  Compensation for use of INRANGE Consolidated Period Tax Items ....     17
   5.4.  Payment of Refunds and Other Tax Benefits ........................     17
   5.5.  Payment for Carrybacks ...........................................     18
   5.6.  Payment for Adjustments on Audit .................................     18
   5.7.  Right to Offset ..................................................     18

SECTION 6.  Assistance and Cooperation ....................................     18

   6.1.  General ..........................................................     18
   6.2.  Tax Return Information; Calculation of Amounts Due ...............     19
</TABLE>




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<TABLE>
<S>                                                                           <C>
SECTION 7.  Tax Records ...............................................       20

   7.2.  Access to Tax Records ........................................       20

SECTION 8.  Control of Tax Contests ...................................       21

SECTION 9.  Survival of Obligations ...................................       21

SECTION 10.  Treatment of Payments; Tax Gross Up ......................       21

   10.1.  Treatment of  Indemnity and Tax Benefit Payments ............       21
   10.2.  Tax Gross Up ................................................       21
   10.3.  Interest Under This Agreement ...............................       22

SECTION 12.  Disagreements ............................................       22

SECTION 13.  Late Payments ............................................       23

SECTION 14.  Expenses .................................................       23

SECTION 15.  Effect on Pre-existing Liabilities .......................       23

SECTION 16.  General Provisions .......................................       23

   16.1. Notices ......................................................       23
   16.2.  Counterparts ................................................       24
   16.3.  Binding Effect; Assignment ..................................       25
   16.4.  Severability ................................................       25
   16.5.  Waiver ......................................................       25
   16.6.  Amendment ...................................................       26
   16.7.  Interpretation ..............................................       26
   16.8.  Effective Time ..............................................       26
   16.9.  Governing Law ...............................................       26
</TABLE>



                                      -ii-


<PAGE>



                              TAX SHARING AGREEMENT


      This Agreement is entered into as of September 18, 2000 by SPX
Corporation, a Delaware corporation ("SPX"), and INRANGE Technologies
Corporation, a Delaware corporation ("INRANGE"). Capitalized terms used in this
Agreement are defined herein. Unless otherwise indicated, all "Section"
references in this Agreement are to sections of this Agreement.


                                    RECITALS

      WHEREAS, INRANGE is currently a wholly-owned subsidiary of SPX;

      WHEREAS, SPX and INRANGE currently contemplate that INRANGE will make an
initial public offering pursuant to the [Prospectus, dated , 2000, of INRANGE]
of [ ] shares of its common stock (the "INITIAL PUBLIC OFFERING") that will
reduce SPX's ownership of INRANGE to not less than 80%; and

      WHEREAS, the Companies desire to provide for and agree upon the allocation
between the parties of liabilities for certain Income Taxes arising prior to, as
a result of, and subsequent to a Deconsolidation, and to provide for and agree
upon other matters relating to such Income Taxes;

      NOW, THEREFORE, in consideration of the premises and the representations,
warranties, covenants and agreements herein contained, and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, and intending to be legally bound hereby, the parties hereby agree
as follows:

SECTION 1. DEFINITION OF TERMS.

      For purposes of this Agreement (including the recitals hereof), the
following terms have the following meanings:

      "ACCOUNTING FIRM" shall have the meaning provided in Section 12.

      "ADJUSTMENT REQUEST" means any formal or informal claim or request filed
with any Tax Authority, or with any administrative agency or court, for the
adjustment, refund, or credit of Income Taxes, including (a) any amended Tax
Return claiming adjustment to the Income Taxes as reported on the Tax Return, or
if applicable, as previously adjusted, or (b) any claim for refund or credit of
Income Taxes previously paid.

      "AFFILIATE" means any entity that directly or indirectly is "controlled"
by the person or entity in question. "Control" means the possession, directly or
indirectly, of the power to direct or cause the direction of the management and
policies of a person, whether through ownership of voting securities, by
contract or otherwise. Except as otherwise provided herein, the term Affiliate
shall refer to Affiliates of a person as determined immediately after the
Deconsolidation.

      "AGREEMENT" means this Tax Sharing Agreement.

      "CARRYBACK" means any net operating loss, net capital loss, tax credit or
other similar Tax Item which may or must be carried from one Tax Period to an
earlier Tax Period under the Code or other applicable Tax Law.

      "CARRYFORWARD" means any net operating loss, net capital loss, tax credit
or other similar Tax Item which may or must be carried from one Tax Period to a
later Tax Period under the Code or other applicable Tax Law.

      "CARRYBACK GROUP" shall have the meaning set forth in Section 4.2(c).

      "CODE" means the U.S. Internal Revenue Code of 1986, as amended from time
to time, or any successor law.

      "COMPANY" means SPX or INRANGE.

      "CONSOLIDATED INCOME TAX RETURN" or "COMBINED INCOME TAX RETURN" means any
Tax Return which is computed by reference to the assets and activities of
members of the SPX Separate Group and the INRANGE Group.


                                      -2-


<PAGE>



      "CONSOLIDATED PERIOD" or "CONSOLIDATED PERIODS" means any Taxable Period
or Periods beginning on or after, or including, the Initial Public Offering
Closing Date in which INRANGE is a member of the SPX Group.

      "CURRENT PERIOD" means the Taxable Period which includes the Initial
Public Offering Closing Date.

      "DECONSOLIDATION" means any event pursuant to which INRANGE ceases to be a
member of the SPX Group.

      "DECONSOLIDATION DATE" means the day on which INRANGE ceases to be a
member of the SPX Group, as determined under Treasury Regulation Section
1.1502-76(b).

      "FEDERAL INCOME TAX" means any Income Tax imposed by the United States
government.

      "INCOME TAX" means all taxes imposed by any governmental entity or
political subdivision thereof (i) based upon, measured by, or calculated with
respect to, net income or net receipts, proceeds or profits or (ii) based upon,
measured by, or calculated with respect to multiple bases (including, but not
limited to, corporate franchise and occupation taxes) if such tax may be based
upon, measured by, or calculated with respect to one or more bases described in
clause (i) above; and, for purposes of both clauses (i) and (ii) above,
including any fee, assessment, or other charge in the nature of or in lieu of
any tax, and any interest, penalties, additions to tax, or additional amounts in
respect of the foregoing.

      "INITIAL PUBLIC OFFERING" shall have the meaning set forth in the
Recitals.

      "INITIAL PUBLIC OFFERING CLOSING DATE" means the date of the closing of
the Initial Public Offering.

      "INTEREST RATE" means the base rate on corporate loans charged by
Citibank, N.A., New York, New York from time to time, compounded on each March
31, June 30, September 30 and December 31.



                                      -3-


<PAGE>



      "INTERNAL REVENUE SERVICE" means the United States Internal Revenue
Service or the United States Department of the Treasury, as the context
requires.

      "INRANGE GROUP" means INRANGE and all corporations included in the INRANGE
Federal Consolidated Return, or, during any Consolidated Period, that would be
included in such Return if INRANGE were not included in the SPX Federal
Consolidated Return.

      "INRANGE FEDERAL CONSOLIDATED RETURN" means any United States federal Tax
Return or Returns in respect of periods after the Consolidated Period filed by
INRANGE alone or by the affiliated group (as that term is defined in Code
Section 1504) that includes INRANGE as the common parent.

      "MEASURING DATE" shall have the meaning set forth in Section 4.1.

      "OTHER GROUP" shall have the meaning set forth in Section 4.2(c).

      "OTHER GROUP CARRYBACK" shall have the meaning set forth in Section
4.2(c).

      "OTHER INCOME TAX" means any Income Tax imposed by any State of the United
States or by any political subdivision of any such State or any any Income Tax
imposed by any foreign country or any possession of the United States, or by any
political subdivision of any foreign country or United States possession.

      "PAYMENT DATE" means (i) with respect to any SPX Federal Consolidated
Return, the due date for any required installment of estimated taxes determined
under Code Section 6655, the due date (determined without regard to extensions)
for filing the return determined under Code Section 6072, and the date the
return is filed, and (ii) with respect to any Consolidated or Combined Income
Tax Return relating to any Other Income Tax, the corresponding dates determined
under the applicable Tax Law.

      "POST-DECONSOLIDATION PERIOD" means any Tax Period beginning after the
Deconsolidation Date, and, in the case of any Straddle Period, the portion of
such Straddle Period beginning the day after the Deconsolidation Date.




                                      -4-


<PAGE>



      "PRE-DECONSOLIDATION PERIOD" means any Tax Period ending on or before the
Deconsolidation Date, and, in the case of any Straddle Period, the portion of
such Straddle Period ending on the Deconsolidation Date.

      "RESPONSIBLE COMPANY" means, with respect to any Tax Return, the Company
having responsibility for preparing and filing such Tax Return under this
Agreement.

      "SPX FEDERAL CONSOLIDATED RETURN" means any United States federal
Consolidated Income Tax Return for the affiliated group (as that term is defined
in Code Section 1504) that includes SPX as the common parent and that includes,
during the Consolidated Periods, the INRANGE Group.

      "SPX GROUP" means all corporations included in the SPX Federal
Consolidated Return.

      "SPX SEPARATE GROUP" shall mean the SPX Group other than members of the
INRANGE Group.

      "STRADDLE PERIOD" means any Tax Period that begins on or before and ends
after the Deconsolidation Date.

      "TAX AUTHORITY" means, with respect to any Income Tax, the governmental
entity or political subdivision thereof that imposes such Income Tax, and the
agency (if any) charged with the collection of such Income Tax for such entity
or subdivision.

      "TAX BENEFIT" means any refund of, credit against, or other reduction in
otherwise required Income Tax payments (including any reduction in estimated tax
payments) and any interest in respect of the foregoing, net of the effect on
otherwise required Income Tax payments of any associated or corresponding item
of income or gain, or other increase in otherwise required Income Tax payments.

      "TAX CONTEST" means an audit, review, examination, or any other
administrative or judicial proceeding with the purpose or effect of
redetermining Income Taxes of any of the




                                      -5-


<PAGE>



Companies or their Affiliates (including any administrative or judicial review
of any claim for refund).

      "TAX ITEM" means, with respect to any Income Tax, any item of income,
gain, loss, deduction, or credit.

      "TAX LAW" means the law of any governmental entity or political
subdivision thereof relating to any Income Tax.

      "TAX PERIOD" or "TAXABLE PERIOD" means, with respect to any Income Tax,
the period for which the Income Tax is reported as provided under the Code or
other applicable Tax Law.

      "TAX RECORDS" means Tax Returns, Tax Return workpapers, documentation
relating to any Tax Contests, and any other books of account or records required
to be maintained under the Code or other applicable Tax Laws or under any record
retention agreement with any Tax Authority.

      "TAX RETURN" means any report of Income Taxes due, any claims for refund
of Income Taxes paid, any information return with respect to Income Taxes, or
any other similar report, statement, declaration, or document required to be
filed under the Code or other Tax Law, including any attachments, exhibits, or
other materials submitted with any of the foregoing, and including any
amendments or supplements to any of the foregoing.

      "TREASURY REGULATIONS" means the regulations promulgated from time to time
under the Code as in effect for the relevant Tax Period.

SECTION 2. ALLOCATION OF INCOME TAX LIABILITIES.

      2.1.  FEDERAL INCOME TAX.

      Except as otherwise provided in this Agreement, Federal Income Tax
liability shall be allocated as follows:

            (a) Consolidated Periods. For each Consolidated Period, INRANGE
      shall be liable for and pay to SPX an amount equal to Federal Income Tax
      determined under the "Stand Alone





                                      -6-


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      Method." Under this method INRANGE's liability for Income Tax for any
      Taxable Period is computed as if, since the Initial Public Offering
      Closing Date, INRANGE had (i) never been part of the SPX Group and (ii)
      filed a federal Consolidated Income Tax Return as parent of the INRANGE
      Group with each eligible member of the INRANGE Group; provided, however,
      that the provisions of Section 2.3(a) regarding special rules for
      application of the Stand Alone Method shall apply. SPX shall be liable for
      all Federal Income Tax for the Consolidated Period other than amounts for
      which INRANGE is liable pursuant to this Section 2.1(a).

            (b) Non-Consolidated Periods. INRANGE shall be responsible for all
      Federal Income Tax imposed on members of the INRANGE Group with respect to
      all periods which are not Consolidated Periods. SPX shall be responsible
      for all Federal Income Tax imposed on members of the SPX Separate Group
      with respect to all periods which are not Consolidated Periods.

    2.2. OTHER INCOME TAXES.

         Except as otherwise provided in this Agreement, the liability for any
Other Income Tax shall be allocated as follows:

            (a) Consolidated or Combined Income Tax Returns. INRANGE shall be
      liable for and pay to SPX any Other Income Tax with respect to any
      Consolidated or Combined Income Tax Return for such Income Taxes in an
      amount that is equal to the amount determined under the Stand Alone Method
      for the period covered by such Tax Return. SPX shall be liable for and pay
      any Other Income Tax with respect to any Consolidated or Combined Income
      Tax Return for such Income Taxes other than the amount for which INRANGE
      is liable pursuant to this Section 2.2.

            (b) Income Tax Returns which are not Consolidated or Combined Income
      Tax Returns. INRANGE shall be responsible for any Other Income Tax imposed
      on members of the INRANGE Group with respect to any Tax Return which is
      not a Consolidated or Combined Income Tax Return. SPX shall be responsible
      for any Other Income Tax imposed on members




                                      -7-


<PAGE>



      of the SPX Group with respect to any Tax Return which is not a
      Consolidated or Combined Income Tax Return.

     2.3. CALCULATION OF INCOME TAX LIABILITY.

            (a) Stand Alone Method. The following rules shall apply for purposes
      of computing INRANGE's liability under the Stand Alone Method - (i) during
      Consolidated Periods all computations shall apply the separate tax
      liability adjustment principles of Treasury Regulation Section
      1.1552-1(a)(2)(ii), or any successor provision thereto, as they would
      apply between (x) the SPX Separate Group and (y) the INRANGE Group, (ii)
      during Consolidated Periods all computations shall be made in conformity
      with the positions, elections and accounting methods used by SPX in
      preparing the Consolidated or Combined Income Tax Returns of the SPX
      Group; (iii) the highest marginal tax rate to which the INRANGE Group
      could be subject under applicable Tax Law shall be deemed to be the only
      Income Tax rate to which such group is subject under such law; and (iv)
      subject to (i) through (iii) above, all computations and other
      determinations shall be made in accordance with the laws and regulations
      applying to affiliated groups filing consolidated returns (including, in
      the case of any company that becomes or ceases to be a member of the SPX
      Group or the INRANGE Group, the laws and regulations applicable to a
      company that becomes or ceases to be a member of such Group), as well as
      all other relevant federal Income Tax laws and regulations (and similar
      rules shall apply in the case of Other Income Taxes in respect to
      Consolidated or Combined Income Tax Returns for such Taxes).

            (b) Allocation of Tax Items.

                  (i) SPX shall allocate Tax Items for the Taxable Period in
            which a Deconsolidation occurs between the Pre-Deconsolidation
            Period of such Taxable Period and the Post-Deconsolidation Period of
            such Taxable Period in accordance with any permitted method under
            the consolidated return provisions of the Code and Treasury
            Regulations.



                                      -8-


<PAGE>



                  (ii) SPX shall allocate Tax Items for the Current Period
            between the portion of such Period ending on the Initial Public
            Offering Closing Date and the portion of such Period beginning after
            the Initial Public Offering Closing Date of such Taxable Period in
            accordance with any method that would be permitted in the event of a
            Deconsolidation.

      2.4. INCOME TAXES FROM THE DISTRIBUTION.

      Notwithstanding anything to the contrary contained herein, SPX shall be
responsible for and pay any and all liability for any Income Taxes of INRANGE
resulting from the distribution on May 19, 2000 by INRANGE of 1000 shares of the
Class A Common Stock of General Signal Healthcare Management, Inc., a Delaware
corporation, to General Signal Holdings Company, the sole stockholder of
INRANGE. This shall include any Income Taxes resulting from any income or gain
recognized under Treasury Regulation Sections 1.1502-13 or 1.1502-19 (or any
corresponding provisions of other applicable Tax Laws) as a result of such
distribution.

      2.5. INCOME TAX PAYMENTS AND INTERCOMPANY BILLINGS.

      Each Company shall pay the Income Taxes allocated to it by this Section 2
either to the applicable Taxing Authority or to the other Company in accordance
with Section 5.

SECTION 3. PREPARATION AND FILING OF TAX RETURNS.

      3.1. GENERAL.

      Except as otherwise provided in this Section 3, Tax Returns shall be
prepared and filed when due (including extensions) by the person obligated to
file such Tax Returns under the Code or applicable Tax Law. The Companies shall
provide, and shall cause their Affiliates to provide, assistance and cooperate
with one another in accordance with Section 6 with respect to the preparation
and filing of Tax Returns, including providing information required to be
provided in Section 6.

     3.2. PRE-DECONSOLIDATION PERIOD AND STRADDLE PERIOD TAX RETURNS.



                                      -9-


<PAGE>



      SPX shall cause to be prepared and filed any Consolidated or Combined
Income Tax Return required to be filed for Pre-Deconsolidation Periods or
Straddle Periods. For each Tax Period or portion thereof for which INRANGE or a
member of the INRANGE Group is included in a Tax Return described in the
preceding sentence, INRANGE shall provide SPX with (i) a true and correct pro
forma tax return for the INRANGE Group together with an accompanying computation
of Tax liability of the INRANGE Group prepared in accordance with the Stand
Alone Method, (ii) separate pro forma tax returns for each member of the INRANGE
Group together with accompanying computations of the separate tax return Tax
liabilities of each member of the INRANGE Group, (iii) a reconciliation of book
income to federal taxable income for each member of the INRANGE Group, and (iv)
any other information or documents reasonably requested by SPX. INRANGE hereby
agrees to provide SPX with such returns and computations no later than the
fifteenth day of the third month following the end of the period to which such
returns and computations relate. Except as otherwise requested by SPX, INRANGE,
in preparing the above mentioned pro forma tax returns for the INRANGE Group,
shall not consider or give effect to any (i) net operating loss carryover or
carryback, (ii) capital loss carryover or carryback, (iii) excess charitable
deduction carryover, (iv) excess tax carryover or carryback or (v) other similar
carryover or carryback items.

      3.3. POST-DECONSOLIDATION PERIOD TAX RETURNS.

      Except as otherwise provided in Section 3.2 with respect to Tax Returns
required to be filed for Straddle Periods:

            (1) All Tax Returns related to INRANGE or the INRANGE Group for
      Post-Deconsolidation Periods shall be prepared and filed (or caused to be
      prepared and filed) by INRANGE,



                                      -10-


<PAGE>



            (2) All Tax Returns related to SPX or the SPX Group, excluding for
      this purpose INRANGE or members of the INRANGE Group, for
      Post-Deconsolidation Periods shall be prepared and filed (or caused to be
      prepared and filed) by SPX.

      3.4. TAX ACCOUNTING PRACTICES.

      Any Tax Return for any Pre-Deconsolidation Period or any Straddle Period,
and any Tax Return for any Post-Deconsolidation Period to the extent items
reported on such Tax Return might reasonably affect items reported on any Tax
Return for any Pre-Deconsolidation Period or any Straddle Period, shall be
prepared in accordance with past Income Tax accounting practices used with
respect to the Tax Returns in question (unless such past practices are no longer
permissible under the Code or other applicable Tax Law), and to the extent any
items are not covered by past practices (or in the event such past practices are
not longer permissible under the Code or other applicable Tax Law), in
accordance with reasonable Income Tax accounting practice selected by the
Responsible Company.

      3.5. RIGHT TO REVIEW TAX RETURNS.

      The Responsible Company with respect to any Tax Return shall make such Tax
Return and related Tax Records available for review by the other Company, if
requested, to the extent (i) such Tax Return relates to Income Taxes for which
the requesting party may be liable, (ii) such Tax Return relates to Income Taxes
for which the requesting party may be liable in whole or in part for any
additional Income Taxes owing as a result of adjustments to the amount of Income
Taxes reported on such Tax Return, (iii) such Tax Return relates to Income Taxes
for which the requesting party may have a claim for Tax Benefits under this
Agreement, or (iv) the requesting party reasonably determines that it must
inspect such Tax Return to confirm compliance with the terms of this Agreement.
The Responsible Company shall use its reasonable best efforts to make such Tax
Return and Tax Records available for review as required under this paragraph
sufficiently in advance of the due date for filing such Tax Returns to provide
the requesting party with a meaningful opportunity to analyze and comment on
such




                                      -11-


<PAGE>



Tax Returns and have such Tax Returns modified before filing, taking into
account the person responsible for payment of the Income Tax (if any) reported
on such Tax Return and the materiality of the amount of Income Tax liability
with respect to such Tax Return. The Companies shall attempt in good faith to
resolve any issues arising out of the review of such Tax Returns or Tax Records.

SECTION 4.  REFUNDS, CARRYBACKS AND TAX BENEFITS.

      4.1. COMPENSATION FOR USE OF INRANGE CONSOLIDATED PERIOD TAX ITEMS.

      In the event that (i) the SPX Group realizes an actual Tax Benefit during
any Consolidated Period as a result of the use by members of the SPX Separate
Group of Tax Items of the INRANGE Group and (ii) the cumulative net amount of
Income Tax borne by the INRANGE Group under Sections 2 and 4 is greater by the
end of any Taxable Period (a "MEASURING DATE") than the amount of the INRANGE
Group's cumulative Income Tax liability through the Measuring Date computed
under the Stand Alone Method (provided, however, that for any
Post-Deconsolidation Period such computation shall be made without regard to
clauses (iii) and (iv) of Section 2.3(a)), then SPX will pay to INRANGE, in
accordance with Section 5.3, an amount equal to the lesser of (x) the excess of
the Tax Benefit actually realized by SPX referred to in clause (i) over the
amount of any prior payments to INRANGE pursuant to this Section 4.1 in respect
of that Tax Benefit and (y) the excess referred to in clause (ii). The
cumulative amounts under the preceding sentence shall be computed beginning on
the Initial Public Offering Closing Date.

      4.2. CLAIMS FOR REFUND, CARRYBACKS, AND SELF-AUDIT ADJUSTMENTS.

            (a) Adjustment Requests Related to Consolidated or Combined Income
      Tax Returns. SPX shall, in its sole absolute discretion, prepare and file
      all Adjustment Requests with respect to any Consolidated or Combined
      Income Tax Return that included the INRANGE Group for a
      Pre-Deconsolidation Period. INRANGE shall provide to SPX all information
      required for the





                                      -12-


<PAGE>



      preparation and filing of such Adjustment Request in such form and detail
      as reasonably requested by SPX.

            (b) Payment of Refunds and other Tax Benefits. Subject to Section
      4.2(c), any refunds or other Tax Benefits received by either Company (or
      any of its Affiliates) as a result of any Adjustment Request which are for
      the account of the other Company (or member of such other Company's Group)
      shall be paid by the Company receiving (or whose Affiliate received) such
      refund or Tax Benefit to such other Company in accordance with Section 5.

            (c) Ordering of and Payment for Carrybacks.

                  (i) In the event that a member of the SPX Separate Group, on
            the one hand, and a member of the INRANGE Group, on the other hand,
            are each entitled to carryback a Tax Item to a Pre-Deconsolidation
            Period, the respective Tax Items shall be used under the rules of
            applicable Tax Law (which shall be, in the case of Carrybacks to
            such Tax Periods of the affiliated group of which SPX is the common
            parent, the rules contained in Treasury Regulation Section
            1.1502-21).

                  (ii) Any Income Tax refund or other Tax Benefit resulting from
            the Carryback of any member of the SPX Group or the INRANGE Group,
            as the case may be (the "CARRYBACK GROUP"), of any Tax Item arising
            after the Deconsolidation Date to a Pre-Deconsolidation Period shall
            be for the account of the Carryback Group (and in the event INRANGE
            Group is the Carryback Group, then upon receipt of the Income Tax
            refund or other Tax Benefit SPX shall pay to INRANGE the amount of
            such Income Tax refund or other Tax Benefit); provided, however,
            that if at the time of the use of the Carryback Tax Items of a
            member of the Carryback Group, a member of the SPX Group or the
            INRANGE Group, as the case may be (the "OTHER GROUP") possesses
            Carryback Tax Items which, but for the ordering rule set forth in
            (i) above, would have been available to be used (the "OTHER GROUP
            CARRYBACK") in lieu of the Carryback Group's Tax Items, then (but
            only to the extent of the Other Group Carryback) the Carryback





                                      -13-


<PAGE>



            Group shall not be entitled to payment of the amount of such Income
            Tax refund or Tax Benefit until the date on which a member of the
            Other Group claims the Other Group Carryback on a Tax Return.

                  (iii) In the event the Carryback of Tax Items of a member of
            the SPX Group or the INRANGE Group, as the case may be, does not
            result in an Income Tax refund, due to an offsetting Income Tax
            adjustment to a member of the Other Group, then the Other Group
            shall promptly pay the amount of any decrease in Income Tax
            liability resulting from the Carryback claim, provided, however,
            that in the event the Other Group possesses Carryback Tax Items
            which, but for the ordering rules set forth in (i) above would have
            been available to be used in lieu of the Carryback Group's Tax
            Items, then (but only to the extent of the Other Group Carryback),
            the Other Group shall not be required to pay the amount of such
            decrease in Income Tax liability to the Carryback Group until the
            date on which a member of the Other Group claims the Other Group
            Carryback on a Tax Return.

      4.3. ADJUSTMENT OF TAX ITEMS.

      In the event that the Carryback of Tax Items of the SPX Group or the
INRANGE Group, as the case may be, or an Income Tax adjustment attributable to
such Group under the terms of this Agreement, results in the disallowance or
limitation of Tax Items claimed on the Tax Return as filed, the Carryback Group
shall be responsible for any increase in Income Tax liability resulting from the
disallowance or limitation of Income Tax attributes; provided, however, that in
the event the disallowance or limitation of Income Tax attributes results in a
Tax Benefit resulting from the use of such Income Tax attributes in another Tax
Period, such Tax Benefit shall be deemed to be for the account of the Carryback
Group for such purposes of this Agreement.

      4.4. ADJUSTMENTS ON AUDIT.

      If, upon examination by any Tax Authority of any Tax Return including a
member of the SPX Group or INRANGE Group for any Tax Period, any item of
deduction, credit or expense is




                                      -14-


<PAGE>



disallowed for which SPX is or may be liable for Income Taxes hereunder (or an
item of income is required to be recognized on a Tax Return which was not
reported on such Tax Return), in either such case resulting in a tax detriment
suffered by the SPX Group, and such disallowance (or recognition) results in a
Tax Benefit to the INRANGE Group (with respect to that Tax Period or another Tax
Period), then INRANGE shall pay to SPX the amount of such Tax Benefit that is
realized in the form of an actual reduction in Income Tax (which shall be
computed by comparing the Income Tax which would have been owed by INRANGE but
for the item giving rise to the Tax Benefit with the Income Tax owed by INRANGE
taking such item into account); provided, however, that in no case will the
amount that INRANGE is required to pay to SPX with respect to such Tax Benefit
exceed the corresponding tax detriment to SPX (reduced by payments previously
made by INRANGE to SPX with respect to such Tax Benefit). Any payment required
to be made hereunder shall be made in accordance with Section 5.6. The
provisions of this Section 4.4 shall apply mutatis mutandis where an item of
deduction, credit or expense is disallowed for which INRANGE is or may be liable
for Income Taxes hereunder (or any item of income is required to be recognized
on a Tax Return which was not reported on such Tax Return), as they apply where
the SPX Group suffers such a detriment. For avoidance of doubt, any payment
required to be made by SPX to the INRANGE Group under this Section 4.4 shall, to
the extent applicable, be deemed as an offset to amounts owing by INRANGE to SPX
under Section 2.1 hereof.

SECTION 5. TAX PAYMENTS AND INTERCOMPANY BILLINGS.

      5.1. PAYMENT OF INCOME TAXES WITH RESPECT TO SPX CONSOLIDATED RETURNS.

      In the case of any Consolidated or Combined Income Tax Return -

            (a) Computation and Payment of Income Tax Due. At least ten business
      days prior to any Payment Date, SPX shall compute the amount of Income Tax
      required to be paid to the applicable Tax Authority (taking into account
      the requirements of Section 3.4 relating to





                                      -15-


<PAGE>



      consistent accounting practices) with respect to such Tax Return on such
      Payment Date and shall notify INRANGE in writing of the amount of Income
      Tax required to be paid on such Payment Date. SPX will pay such amount to
      the applicable Tax Authority on or before such Payment Date.

            (b) Computation and Payment of INRANGE Liability With Respect to
      Income Tax Due. Within 15 days following any Payment Date, INRANGE will
      pay to SPX the excess (if any) of

                  (i) the amount of liability determined as of such Payment Date
            with respect to the applicable Tax Period allocable to INRANGE in a
            manner consistent with the provisions of Section 2, over

                  (ii) the amount equal to the cumulative net payments with
            respect to such Tax Return prior to such Payment Date made by
            INRANGE or members of INRANGE Group.

If the amount in clause (ii) above is greater than the amount in clause (i)
above as of any Payment Date, then SPX shall pay such excess to INRANGE within
15 days following the Payment Date.

            (c) Interest on Intergroup Tax Allocation Payments. In the case of
      any payments to SPX required under paragraph (b) of this Section 5.1,
      INRANGE shall also pay to SPX an amount of interest computed at the
      Interest Rate on the amount of the payment required based on the number of
      days from the applicable Payment Date until the date of INRANGE's
      subsequent payment. In the case of any payments by SPX required under
      paragraph (b) of this Section 5.1, SPX shall also pay to INRANGE an amount
      of interest computed at the Interest Rate on the amount of the payment
      required based on the number of days from the applicable Payment Date
      until the date of SPX's subsequent payment of such amount to INRANGE.

      5.2. PAYMENT OF INCOME TAX RELATED TO ADJUSTMENTS.



                                      -16-


<PAGE>



            (a) Adjustments Resulting in Underpayments. SPX shall pay to the
      applicable Tax Authority when due any additional Income Tax required to be
      paid as a result of any adjustment to the tax liability with respect to
      any Consolidated or Combined Income Tax Return. INRANGE shall pay to SPX
      an amount equal to the increase in the liability of INRANGE under Sections
      2 and 4 as a result of any adjustment within 15 days from the date of
      receipt by INRANGE of a written notice and demand from SPX for payment of
      the amount due, describing in reasonable detail the particulars relating
      thereto, and, in the event any additional Income Tax was paid by SPX,
      evidence of payment and a statement detailing the Income Taxes paid. Any
      payments required under this Section 5.2(a) shall include interest
      computed at the Interest Rate based on the number of days from the date
      any additional Income Tax was paid by SPX to the date of the payment under
      this Section 5.2(a).

            (b) Adjustments Resulting in Overpayments. Within 15 days of receipt
      by SPX of any Tax Benefit or the reduction of the amounts owed by INRANGE
      to SPX under Sections 2 and 4 resulting from any adjustment to the tax
      liability with respect to any Consolidated or Combined Income Tax Return,
      SPX shall pay to INRANGE its share of any such Tax Benefit or the amount
      of such reduction, as determined in accordance with the principles of
      Sections 2 and 4. Any payments required under this Section 5.2(b) shall
      include interest computed at the Interest Rate based on the number of days
      from the date the Tax Benefit was received by SPX to the date of payment
      to INRANGE under this Section 5.2(b).


      5.3. COMPENSATION FOR USE OF INRANGE CONSOLIDATED PERIOD TAX ITEMS.

      In the event SPX is required to pay INRANGE in accordance with Section
4.1, SPX shall pay INRANGE within 15 days from the due date (including any
extensions) for the Tax Return filed with respect to such amount, including
interest computed at the Interest Rate based on the number of days from such due
date to the date SPX pays INRANGE.

      5.4. PAYMENT OF REFUNDS AND OTHER TAX BENEFITS.



                                      -17-


<PAGE>



            (a) Except as otherwise provided in this Agreement, if a member of
      the SPX Group or the INRANGE Group, as the case may be, receives an Income
      Tax refund or other Tax Benefit with respect to Income Taxes for which a
      member of the other Group is liable hereunder, the Company receiving such
      Income Tax refund shall make a payment to the Company who is liable for
      such Income Taxes hereunder within 15 days following the receipt of the
      Income Tax refund in an amount equal to such Income Tax refund, plus
      interest on such amount computed at the Interest Rate based on the number
      of days from the date of receipt of the Income Tax refund to the date of
      payment under this Section 5.4.

            (b) In the event the SPX Group or the INRANGE Group, as the case may
      be, is reimbursed for its payment of an Income Tax liability of the other
      Group, the amount of such reimbursement shall be computed net of any Tax
      Benefit realized by the reimbursed Group as the result of payment of the
      other Group's Income Tax liability.

      5.5. PAYMENT FOR CARRYBACKS.

      Each Company shall pay the other Company for Carrybacks in accordance with
Section 4.2(c). Any such payment shall include interest at the Interest Rate
based on the number of days from the date the Company is required to make the
payment under Section 4.2(c) to the date the Company actually makes the payment.

      5.6. PAYMENT FOR ADJUSTMENTS ON AUDIT.

      Any payment required under Section 4.4 shall be made within 15 days of the
due date (including any extensions) of the Tax Return on which the Tax Benefit
described in that section is claimed. Such payment shall include interest
computed at the Interest Rate based on the number of days from such due date to
the date the payment is made.

      5.7. RIGHT TO OFFSET.

      Notwithstanding anything to the contrary contained herein, SPX or INRANGE,
as applicable, may, in lieu of cash payment, offset any obligation owed to such
Company by the





                                      -18-


<PAGE>



other Company pursuant to this Agreement against any obligation owed by such
Company to the other Company pursuant to this Agreement.

SECTION 6. ASSISTANCE AND COOPERATION.

      6.1. GENERAL.

      Each of the Companies shall cooperate (and cause their respective
Affiliates to cooperate) with each other and with each other's agents, including
accounting firms and legal counsel, regarding the application of all aspects of
this Agreement in connection with Income Tax matters relating to the Companies
and their Affiliates including (i) preparation and filing of Tax Returns, (ii)
determining the liability for and amount of any Income Taxes due (including
estimated Income Taxes) or the right to and amount of any refund of Income
Taxes, (iii) examinations of Tax Returns, and (iv) any administrative or
judicial proceeding in respect of Income Taxes assessed or proposed to be
assessed. Such cooperation shall include (i) making all information and
documents in their possession relating to the other Companies and their
Affiliates available to such other Companies as provided in Section 7, (ii) the
execution of any Tax Return which is required to be prepared and filed by one
Company under this Agreement and which is required by law to be signed by
another Company (or by its authorized representative), and (iii) providing
notice to the other party of any pending or threatened Income Tax audit,
assessment or proceeding or other Tax Contest of which it becomes aware related
to Income Taxes for which the other party is responsible. Each of the Companies
shall also make available to each other, as reasonably requested and available,
personnel (including officers, directors, employees and agents of the Companies
or their respective Affiliates) responsible for preparing, maintaining, and
interpreting information and documents relevant to Income Taxes, and personnel
reasonably required as witnesses or for purposes of providing information or
documents in connection with any administrative or judicial proceedings relating
to Income Taxes. Any information or documents provided under this Section 6
shall be kept confidential by the Company receiving the




                                      -19-


<PAGE>



information or documents, except as may otherwise be necessary in connection
with the filing of Tax Returns or in connection with any administrative or
judicial proceedings relating to Income Taxes.

      6.2. TAX RETURN INFORMATION; CALCULATION OF AMOUNTS DUE.

            (a) Each Company will provide (and cause their respective Affiliates
      to provide) to each other Company information and documents relating to
      their respective Groups required by the other Companies to prepare Tax
      Returns. The Responsible Company shall determine a reasonable compliance
      schedule for such purpose in accordance with past practices. Any
      additional information or documents the Responsible Company requires to
      prepare such Tax Returns will be provided in accordance with past
      practices, if any, or as the Responsible Company reasonably requests and
      in sufficient time for the Responsible Company to timely file such Tax
      Returns.

            (b) SPX or INRANGE, as applicable, shall promptly provide (and cause
      their respective Affiliates to promptly provide) to the other Company upon
      such other Company's reasonable request all information and documents as
      such other Company deems reasonably necessary to compute the amount of any
      payment provided for under this Agreement.

SECTION 7. TAX RECORDS.

      Each Company shall preserve and keep all Tax Records exclusively relating
to the assets and activities of their respective Groups for Pre-Deconsolidation
Tax Periods, and SPX shall preserve and keep all other Tax Records relating to
Income Taxes of the SPX Group for Pre-Deconsolidation Tax Periods, for so long
as the contents thereof may become material in the administration of any matter
under the Code or other applicable Tax Law, but in any event until the later of
(i) the expiration of any applicable statutes of limitation, as extended, and
(ii) seven years after the filing of the Tax Returns to which such Tax Records
relate. If, prior to the expiration of the applicable statute of limitation and
such seven-year period, a Company




                                      -20-


<PAGE>



reasonably determines that any Tax Records which it is required to preserve and
keep under this Section 7 are no longer material in the administration of any
matter under the Code or other applicable Tax Law, such Company may dispose of
such records upon 90 days prior written notice to the other Company. Such notice
shall include a list of the records to be disposed of describing in reasonable
detail each file, book, or other record accumulation being disposed. The
notified Company shall have the opportunity, at its cost and expense, to copy or
remove, within such 90-day period, all or any part of such Tax Records.

      7.2. ACCESS TO TAX RECORDS.

      The Companies shall, and shall cause their respective Affiliates to, make
available to each other for inspection and copying during normal business hours
upon reasonable notice all Tax Records in their possession to the extent
reasonably requested by the other Company in connection with the preparation of
Tax Returns, audits, litigation, or the resolution of items under this
Agreement.

SECTION 8. CONTROL OF TAX CONTESTS.

      Each Company shall have full responsibility and discretion in handling,
settling or contesting any Tax Contest involving an Income Tax for which it is
liable pursuant to Section 2 of this Agreement; provided, however, SPX shall
have full responsibility and discretion in handling, settling or contesting any
Tax Contest with respect to a Consolidated or Combined Income Tax Return of the
SPX Group.

SECTION 9. SURVIVAL OF OBLIGATIONS.

      The representations, warranties, covenants and agreements set forth in
this Agreement shall be unconditional and absolute and shall remain in effect
without limitation as to time.

SECTION 10. TREATMENT OF PAYMENTS; TAX GROSS UP.

      10.1. TREATMENT OF INDEMNITY AND TAX BENEFIT PAYMENTS.



                                      -21-


<PAGE>



      In the absence of any change in tax treatment under the Code or other
applicable Tax Law, any Income Tax indemnity payments or Tax Benefit payments
made by a Company under Section 5 shall be reported for Income Tax purposes by
the payor and the recipient as distributions or capital contributions, as
appropriate, occurring immediately before the Deconsolidation on the
Deconsolidation Date, but only to the extent the payment does not relate to a
Tax allocated to the payor in accordance with Treasury Regulation Section
1.1502-33(d) (or under corresponding principles of other applicable Tax Laws).

      10.2. TAX GROSS UP.

      If notwithstanding the manner in which Income Tax indemnity payments and
Tax Benefit payments were reported, there is an adjustment to the Income Tax
liability of a Company as a result of its receipt of a payment pursuant to this
Agreement, such payment shall be appropriately adjusted so that the amount of
such payment, reduced by the amount of all Income Taxes payable with respect to
the receipt thereof (but taking into account all correlative Tax Benefits
resulting from the payment of such Income Taxes), shall equal the amount of the
payment which the Company receiving such payment would otherwise be entitled to
receive pursuant to this Agreement.

      10.3. INTEREST UNDER THIS AGREEMENT.

      Anything herein to the contrary notwithstanding, to the extent one Company
("indemnitor") makes a payment of interest to another Company ("indemnitee")
under this Agreement with respect to the period from the date that the
indemnitee made a payment of Income Tax to a Tax Authority to the date that the
indemnitor reimbursed the indemnitee for such Income Tax payment, or with
respect to the period from the date that the indemnitor received a Tax Benefit
to the date indemnitor paid the indemnitee with respect to such Tax Benefit, the
interest payment shall be treated as interest expense to the indemnitor
(deductible to the extent provided by law) and as interest income by the
indemnitee (includible in income to the extent provided by law). The amount of
the payment shall not be adjusted under Section 10.2 to




                                      -22-


<PAGE>



take into account any associated Tax Benefit to the indemnitor or increase in
Income Tax to the indemnitee.

SECTION 12. DISAGREEMENTS.

      If after good faith negotiations the parties cannot agree on the
application of this Agreement to any matter, then the matter will be referred to
an accounting firm acceptable to each of the parties (the "ACCOUNTING FIRM").
The Accounting Firm shall furnish written notice to the parties of its
resolution of any such disagreement as soon as practical, but in any event no
later than 45 days after its acceptance of the matter for resolution. Any such
resolution by the Accounting Firm will be conclusive and binding on all parties
to this Agreement. In accordance with Section 14, each party shall pay its own
fees and expenses (including the fees and expenses of its representatives)
incurred in connection with the referral of the matter to the Accounting Firm.
All fees and expenses of the Accounting Firm in connection with such referral
shall be shared equally by the parties affected by the matter.

SECTION 13. LATE PAYMENTS.

      Any amount owed by one party to another party under this Agreement which
is not paid when due shall bear interest at the Interest Rate plus two percent,
compounded on each March 31, June 30, September 30 and December 31, from the due
date of the payment to the date paid. To the extent interest required to be paid
under this Section 13 duplicates interest required to be paid under any other
provision of this Agreement, interest shall be computed at the higher of the
interest rate provided under this Section 13 or the interest rate provided under
such other provision.

SECTION 14. EXPENSES.

      Except as provided in Section 13, each Company and its Affiliates shall
bear their own expenses incurred in connection with preparation of Tax Returns,
Tax Contests, and other matters related to Income Taxes under the provisions of
this Agreement.




                                      -23-


<PAGE>



SECTION 15. EFFECT ON PRE-EXISTING LIABILITIES.

      This Agreement shall not effect the liabilities of any member of the SPX
Group existing on or prior to the Initial Public Offering Closing Date under any
tax sharing agreement, tax indemnification agreement, or other similar
agreement.

SECTION 16. GENERAL PROVISIONS.

      16.1. NOTICES.

      All notices and other communications hereunder shall be in writing and
shall be delivered in person, by telecopy, by express or overnight mail
delivered by a nationally recognized air courier (delivery charges prepaid), or
by registered or certified mail (postage prepaid, return receipt requested) to
the respective parties as follows:

      (a)   If to SPX, to:

                  SPX Corporation
                  700 Terrace Point Drive
                  P.O. Box 3301
                  Muskegan, Michigan 49443
                  Attention: Christopher J. Kearney, Esq.

      (b)   If to INRANGE, to:

                  INRANGE Technologies Corporation
                  13000 Midlantic Drive
                  Mt. Laurel, New Jersey 08054
                  Attention: Kenneth H. Koch, Esq.



                                      -24-


<PAGE>



or to such other address as the party to whom notice is given may have
previously furnished to the others in writing in the manner set forth above. Any
notice or communication delivered in person shall be deemed effective on
delivery or when delivery is refused. Any notice or communication sent by
telecopy or by air courier shall be deemed effective on the first business day
at the place at which such notice or communication is received following the day
on which such notice or communication was sent.

      16.2. COUNTERPARTS.

      This Agreement may be executed in two or more counterparts, each of which
shall be deemed to be an original, but all of which together shall constitute
one and the same agreement. The Agreement may be delivered by facsimile
transmission of a signed copy thereof.

      16.3. BINDING EFFECT; ASSIGNMENT.

      This Agreement and all of the provisions hereof shall be binding upon the
parties hereto and inure to the benefit of the parties hereto and their
respective successors and permitted assigns. Except with respect to a merger of
either party, neither this Agreement nor any of the rights, interests or
obligations hereunder shall be assigned by either party hereto without the prior
written consent of the other party, which consent shall not be unreasonably
withheld or delayed; provided, however, that SPX and INRANGE may assign their
respective rights, interests, duties, liabilities and obligations under this
Agreement to any of their respective subsidiaries, but such assignment shall not
relieve SPX or INRANGE, as the assignee, of its obligations hereunder.

      16.4. SEVERABILITY.

      Any provision of this Agreement which is prohibited or unenforceable in
any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of
such prohibition or unenforceability without invalidating the remaining
provisions hereof. Any such prohibition or unenforceability in any jurisdiction
shall not invalidate or render unenforceable such provision in any other
jurisdiction.



                                      -25-


<PAGE>



      16.5. WAIVER.

      The observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or prospectively)
by the party entitled to enforce such term, but such waiver shall be effective
only if it is in writing signed by the party against which such waiver is to be
asserted. Unless otherwise expressly provided in this Agreement, no delay or
omission on the part of any party in exercising any right or privilege under
this Agreement shall operate as a waiver thereof, nor shall any waiver on the
part of any party of any right or privilege under this Agreement operate as a
waiver of any other right or privilege under this Agreement nor shall any single
or partial exercise of any right or privilege preclude any other or further
exercise thereof or the exercise of any other right or privilege under this
Agreement. No failure by either party to take any action or assert any right or
privilege hereunder shall be deemed to be a waiver of such right or privilege in
the event of the continuation or repetition of the circumstances giving rise to
such right unless expressly waived in writing by the party against whom the
existence of such waiver is asserted.

      16.6. AMENDMENT.

      This Agreement may not be amended or modified in any respect except by a
written agreement signed by both of the parties hereto.

      16.7. INTERPRETATION.

      The headings contained in this Agreement and in the table or contents to
this Agreement are for reference purposes only and shall not affect in any way
the meaning or interpretation of this Agreement. When a reference is made in
this Agreement to a Section, such reference shall be to a Section of this
Agreement unless otherwise indicated.

      16.8. EFFECTIVE TIME.

      This Agreement shall become effective upon the Initial Public Offering
Closing Date.

      16.9. GOVERNING LAW.



                                      -26-


<PAGE>



      This Agreement shall be governed by, and construed in accordance with, the
domestic laws of the State of Delaware, without giving effect to any choice of
law or conflict of law provision or rule (whether of the State of Delaware or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Delaware.






                                      -27-


<PAGE>


      IN WITNESS WHEREOF, the parties have caused this Agreement to be executed
by the respective officers as of the date set forth above.

                                 SPX CORPORATION


                                 By: /s/ Christopher J. Kearney
                                    ---------------------------

                                     Name: Christopher J. Kearney
                                     Title: Vice President and General Counsel

                                 INRANGE TECHNOLOGIES CORPORATION

                                 By: /s/ Kenneth H. Koch
                                    -------------------------

                                    Name: Kenneth H. Koch
                                    Title: Vice President and General Counsel