Document:

<PAGE>

                                                                   EXHIBIT 10.19

                                                        SERVICE PACKAGE NO. 8518
                                                                 AMENDMENT NO. 0

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

THIS AGREEMENT is made and entered into as of the 1st day of November, 1994, by
and between TENNESSEE GAS PIPELINE COMPANY, a Delaware Corporation, hereinafter
referred to as "Transporter" and ESSEX COUNTY GAS CO., a MASSACHUSETTS
Corporation, hereinafter referred to as "Shipper." Transporter and Shipper shall
collectively be referred to herein as the "Parties."

                                    ARTICLE I

                                   DEFINITIONS

1.1   TRANSPORTATION QUANTITY (TQ) - shall mean the maximum daily quantity of
      gas which Transporter agrees to receive and transport on a firm basis,
      subject to Article II herein, for the account of Shipper hereunder on each
      day during each year during the term hereof, which shall be 15,728
      dekatherms. Any limitations of the quantities to be received from each
      Point of Receipt and/or delivered to each Point of Delivery shall be as
      specified on Exhibit "A" attached hereto.

1.2   EQUIVALENT QUANTITY - shall be as defined in Article I of the General
      Terms and Conditions of Transporter's FERC Gas Tariff.

                                   ARTICLE II

                                 TRANSPORTATION

Transportation Service - Transporter agrees to accept and receive daily on a
firm basis, at the Point(s) of Receipt from Shipper or for Shipper's account
such quantity of gas as Shipper makes available up to the Transportation
Quantity, and to deliver to or for the account of Shipper to the Point(s) of
Delivery an Equivalent Quantity of gas.

                                   ARTICLE III

                        POINT(S) OF RECEIPT AND DELIVERY

The Primary Point(s) of Receipt and Delivery shall specified on Exhibit "A"
attached hereto.

                                   ARTICLE IV

All facilities are in place to render the service provided for in this
Agreement.

                                       1
<PAGE>

                                                        SERVICE PACKAGE NO. 8518
                                                                 AMENDMENT NO. 0

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

                                    ARTICLE V

              QUALITY SPECIFICATIONS AND STANDARDS FOR MEASUREMENT

For all gas received, transported and delivered hereunder the Parties agree to
the Quality Specifications and Standards for Measurement as specified in the
General Terms and Conditions of Transporter's FERC Gas Tariff Volume No. 1. To
the extent that no new measurement facilities are installed to provide service
hereunder, measurement operations will continue in the manner in which they have
previously been handled. In the event that such facilities are not operated by
Transporter or a downstream pipeline, then responsibility for operations shall
be deemed to be Shipper's.

                                   ARTICLE VI

                    RATES AND CHARGES FOR GAS TRANSPORTATION

6.1   TRANSPORTATION RATES - Commencing upon the effective date hereof, the
      rates, charges, and surcharges to be paid by Shipper to Transporter for
      the transportation service provided herein shall be in accordance with
      Transporter's Rate Schedule FT-A and the General Terms and Conditions of
      Transporter's FERC Gas Tariff.

6.2   INCIDENTAL CHARGES - Shipper agrees to reimburse Transporter for any
      filing or similar fees, which have not been previously paid for by
      Shipper, which Transporter incurs in rendering service hereunder.

6.3   CHANGES IN RATES AND CHARGES - Shipper agrees that Transporter shall have
      the unilateral right to file with the appropriate regulatory authority and
      make effective changes in (a) the rates and charges applicable to service
      pursuant to Transporter's Rate Schedule FT-A, (b) the rate schedule(s)
      pursuant to which service hereunder is rendered, or (c) any provision of
      the General Terms and Conditions applicable to those rate schedules.
      Transporter agrees that Shipper may protest or contest the aforementioned
      filings, or may seek authorization from duly constituted regulatory
      authorities for such adjustment of Transporter's existing FERC Gas Tariff
      as may be found necessary to assure Transporter just and reasonable rates.

                                   ARTICLE VII

                              BILLINGS AND PAYMENTS

Transporter shall bill and Shipper shall pay all rates and charges in accordance
with Articles V and VI, respectively, of the General Terms and Conditions of
Transporter's FERC Gas Tariff.

                                       2
<PAGE>

                                                        SERVICE PACKAGE NO. 8518
                                                                 AMENDMENT NO. 0

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

                                  ARTICLE VIII

                          GENERAL TERMS AND CONDITIONS

This Agreement shall be subject to the effective provisions of Transporter's
Rate Schedule FT-A and to the General Terms and Conditions incorporated
therein, as the same may be changed or superseded from time to time in
accordance with the rules and regulations of the FERC.

                                   ARTICLE IX

                                   REGULATION

9.1   This Agreement shall be subject to all applicable and lawful governmental
      statutes, orders, rules and regulations and is contingent upon the receipt
      and continuation of all necessary regulatory approvals or authorizations
      upon terms acceptable to Transporter. This Agreement shall be void and of
      no force and effect if any necessary regulatory approval is not so
      obtained or continued. All Parties hereto shall cooperate to obtain or
      continue all necessary approvals or authorizations, but no Party shall be
      liable to any other Party for failure to obtain or continue such approvals
      or authorizations.

9.2   The transportation service described herein shall be provided subject to
      Subpart G, Part 284, of the FERC Regulations.

                                    ARTICLE X

                      RESPONSIBILITY DURING TRANSPORTATION

Except as herein specified, the responsibility for gas during transportation
shall be as stated in the General Terms and Conditions of Transporter's FERC Gas
Tariff Volume No. 1.

                                   ARTICLE XI

                                   WARRANTIES

11.1  In addition to the warranties set forth in Article IX of the General Terms
      and Conditions of Transporter's FERC Gas Tariff, Shipper warrants the
      following:

      (a)   Shipper warrants that all upstream and downstream transportation
            arrangements are in place, or will be in place as of the requested
            effective date of service, and that it has advised the upstream and
            downstream transporters of the receipt and delivery points under
            this Agreement and any quantity limitations for each point as
            specified on Exhibit "A" attached hereto. Shipper agrees to
            indemnify and hold Transporter harmless for refusal to transport gas
            hereunder in the event any upstream or downstream transporter fails
            to

                                       3
<PAGE>

                                                        SERVICE PACKAGE NO. 8518
                                                                 AMENDMENT NO. 0

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

            receive or deliver gas as contemplated by this Agreement.

      (b)   Shipper agrees to indemnify and hold Transporter harmless from all
            suits, actions, debts, accounts, damages, costs, losses and expenses
            (including reasonable attorneys fees) arising from or out of breach
            of any warranty by Shipper herein.

11.2  Transporter shall not be obligated to provide or continue service
      hereunder in the event of any breach of warranty.

                                   ARTICLE XII

                                      TERM

12.1  This Agreement shall be effective as of the 1st day of November, 1994, and
      shall remain in force and effect until the 1st day of November, 2000,
      ("Primary Term") and on a month to month basis thereafter unless
      terminated by either Party upon at least thirty (30) days prior written
      notice to the other Party; provided, however, that if the Primary Term is
      one year or more, then unless Shipper elects upon one year's prior written
      notice to Transporter to request a lesser extension term, the Agreement
      shall automatically extend upon the expiration of the Primary Term for a
      term of five years and shall automatically extend for successive five year
      terms thereafter unless Shipper provides notice described above in advance
      of the expiration of a succeeding term; provided further, if the FERC or
      other governmental body having jurisdiction over the service rendered
      pursuant to this Agreement authorizes abandonment of such service, this
      Agreement shall terminate on the abandonment date permitted by the FERC or
      such other governmental body.

12.2  Any portions of this Agreement necessary to resolve or cash-out imbalances
      under this Agreement as required by the General Terms and Conditions of
      Transporter's FERC Gas Tariff Volume No. 1, shall survive the other parts
      of this Agreement until such time as such balancing has been accomplished;
      provided, however, that Transporter notifies Shipper of such imbalance no
      later than twelve months after the termination of this Agreement.

12.3  This Agreement will terminate automatically upon written notice from
      Transporter in the event Shipper fails to pay all of the amount of any
      bill for service rendered by Transporter hereunder in accord with the
      terms and conditions of Article VI of the General Terms and Conditions of
      Transporter's FERC Tariff.

                                       4
<PAGE>

                                                        SERVICE PACKAGE NO. 8518
                                                                 AMENDMENT NO. 0

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

                                  ARTICLE XIII

                                     NOTICE

Except as otherwise provided in the General Terms and Conditions applicable to
this Agreement, any notice under this Agreement shall be in writing and mailed
to the post office address of the Party intended to receive the same, as
follows:

TRANSPORTER:    TENNESSEE GAS PIPELINE COMPANY
                P.O. Box 2511
                Houston, Texas 77252-2511
                Attention: Transportation Marketing

SHIPPER:

NOTICES:        ESSEX COUNTY GAS CO
                7 NORTH HUNT ROAD

                AMESBURY, MA 01913
                Attention: ALLEN R. NEALE

BILLING:        ESSEX COUNTY GAS CO
                P.O. BOX 500
                7 NORTH HUNT ROAD

                AMESBURY, MA 01913
                Attention: JOHN J. CAMERON

or to such other address as either Party shall designate by formal written
notice to the other.

                                   ARTICLE XIV

                                   ASSIGNMENTS

14.1  Either Party may assign or pledge this Agreement and all rights and
      obligations hereunder under the provisions of any mortgage, deed of trust,
      indenture, or other instrument which it has executed or may execute
      hereafter as security for indebtedness. Either Party may, without
      relieving itself of its obligation under this Agreement, assign any of its
      rights hereunder to a company with which it is affiliated. Otherwise,
      Shipper shall not assign this Agreement or any of its rights hereunder,
      except in accord with Article III, Section 11 of the General Terms and
      Conditions of Transporter's FERC Gas Tariff.

14.2  Any person which shall succeed by purchase, merger, or consolidation to
      the properties, substantially as an entirety, of either Party hereto shall
      be entitled to the rights and shall be subject to the obligations of its
      predecessor in interest under this Agreement.

                                       5
<PAGE>

                                                        SERVICE PACKAGE NO. 8518
                                                                 AMENDMENT NO. 0

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

                                   ARTICLE XV

                                  MISCELLANEOUS

15.1  The interpretation and performance of this Agreement shall be in
      accordance with and controlled by the laws of the State of Texas, without
      regard to the doctrines governing choice of law.

15.2  If any provisions of this Agreement is declared null and void, or
      voidable, by a court of competent jurisdiction, then that provision will
      be considered severable at either Party's option; and if the severability
      option is exercised, the remaining provisions of the Agreement shall
      remain in full force and effect.

15.3  Unless otherwise expressly provided in this Agreement or Transporter's Gas
      Tariff, no modification of or supplement to the terms and provisions
      stated in this agreement shall be or become effective until Shipper has
      submitted a request for change through the TENN-SPEED 2 System and Shipper
      has been notified through TENN-SPEED 2 of Transporter's agreement to such
      change.

15.4  Exhibit "A" attached hereto is incorporated herein by reference and made a
      part hereof for all purposes.

IN WITNESS WHEREOF, the Parties hereto have caused this Agreement to be duly
executed as of the date first hereinabove written.

     TENNESSEE GAS PIPELINE COMPANY

     BY: /s/ Byron S. Wright
         ------------------------------
     Agent and Attorney-in-Fact
     Byron S. Wright

     ESSEX COUNTY GAS CO

     BY: /s/ Allen R. Neale
         ------------------------------
     TITLE: Vice-President
           ----------------------------
     DATE: 4/18/95
          -----------------------------

                                       6
<PAGE>

                          GAS TRANSPORTATION AGREEMENT
                       (For Use Under FT-A Rate Schedule)

                                   EXHIBIT "A"
                  AMENDMENT #0 TO GAS TRANSPORTATION AGREEMENT
                             DATED November 1, 1994
                                     BETWEEN
                         TENNESSEE GAS PIPELINE COMPANY
                                       AND
                               ESSEX COUNTY GAS CO

ESSEX COUNTY GAS CO
EFFECTIVE DATE OF AMENDMENT: November 1, 1994
TE SCHEDULE: FT-A
SERVICE PACKAGE: 8518
SERVICE PACKAGE TQ: 15,728 Dth

<TABLE>
<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                      COUNTY          ST     ZONE  R/D    LEG
------------------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                          <C>             <C>     <C>    <C>  <C>
0807    SAMEDAN-BRAZOS BLK A-52 C                                                            OFFSHORE-FEDERA OT      00     R    100
1034    SEAGULL OPERATING - GALVESTON I         SEAGULL ENERGY E&P INC                       OFFSHORE-FEDERA OT      00     R    100
1366    TRANSCONTINENTAL - UTOS EXCHAN                                                       CAMERON         LA      01     R    800
0454    AMERICAN-N KEERAN WELL                  ROCKLAND PIPELINE COMPANY                    VICTORIA        TX      00     R    100
0688    APACHE-LAKE RACCOURCI DEHYD             APACHE CORPORATION                           LAFOURCHE       LA      01     R    500
0734    VALLEY-HACKBERRY DEHYD TRANS            VALLEY GAS TRANSMISSION INC                  CAMERON         LA      01     R    800
0864    KOCH-MONROE DEHYD TRANS                 KOCH GATEWAY PIPELINE COMPANY                OUACHITA        LA      01     R    100
1119    CHEVRON-S MARSH IS BLK 61 C             LOUISIANA LAND AND EXPLORATION               OFFSHORE-FEDERA OL      01     R    500
1306    CHANNEL-AGUA DULCE EXCH                 CHANNEL INDUSTRIES GAS CO                    NUECES          TX      00     R    100
1330    FITE-CHEMARD LAKE DEHYD                 FITE OIL & GAS INC                           DE SOTO         LA      01     R    100
1353    AMOCO-EUGENE IS BLK 322 A               AMOCO PRODUCTION CO                          OFFSHORE-FEDERA OL      01     R    500
1488    SOUTHERN-TOCA EXCH                      SOUTHERN NATURAL GAS CO                      ST BERNARD      LA      01     R    500
1972    GREAT - SOUTH MARSH ISLAND 798          GREAT WESTERN OFFSHORE INC                   OFFSHORE-FEDERA OL      01     R    500
2011    ENERGY - VERMILLION 117 (119G)          ENERGY DEVELOPMENT CORP                      OFFSHORE-FEDERA OL      01     R    800
2020    TRANSCO - FALFURRIAS TRANSPORT                                                       JIM WELLS       TX      00     R    100
2       FOREST - EUGENE ISLAND BLK 325          FOREST OIL CORP                              OFFSHORE-FEDERA OL      01     R    500
2       VALERO - MONTE CHRISTO EXCHANG          VALERO TRANSMISSION LP                       HIDALGO         TX      00     R    100
2273    ZILKHA - WEST CAMERON 53                                                             OFFSHORE-FEDERA OL      01     R    800
2298    M W - WELCH DEHYDRATION                                                              JEFFERSON DAVIS LA      01     R    500
8029    COLUMBIA SHIP SHOAL BLK 247F                                                         OFFSHORE-FEDERA OL      01     R    500

                                                                                                                   Total Receipt TQ:

0122    ESSEX-HAVERHILL SMS                     ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200
0138    ESSEX-WENHAM MASS                       ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200
0323    ESSEX-ESSEX MASS                        ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200

<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                              METER-TQ    Minimum Pressure
------------------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                                    <C>          <C>
0807    SAMEDAN-BRAZOS BLK A-52 C                                                                         881
1034    SEAGULL OPERATING - GALVESTON I         SEAGULL ENERGY E&P INC                                    353
1366    TRANSCONTINENTAL - UTOS EXCHAN                                                                  1,343
0454    AMERICAN-N KEERAN WELL                  ROCKLAND PIPELINE COMPANY                                 219
0688    APACHE-LAKE RACCOURCI DEHYD             APACHE CORPORATION                                        569
0734    VALLEY-HACKBERRY DEHYD TRANS            VALLEY GAS TRANSMISSION INC                               926
0864    KOCH-MONROE DEHYD TRANS                 KOCH GATEWAY PIPELINE COMPANY                             309
1119    CHEVRON-S MARSH IS BLK 61 C             LOUISIANA LAND AND EXPLORATION                          1,940
1306    CHANNEL-AGUA DULCE EXCH                 CHANNEL INDUSTRIES GAS CO                               2,110
1330    FITE-CHEMARD LAKE DEHYD                 FITE OIL A GAS INC                                         90
1353    AMOCO-EUGENE IS BLK 322 A               AMOCO PRODUCTION CO                                     1,592
1488    SOUTHERN-TOCA EXCH                      SOUTHERN NATURAL GAS CO                                 1,100
1972    GREAT - SOUTH MARSH ISLAND 798          GREAT WESTERN OFFSHORE INC                                306
2011    ENERGY - VERMILLION 117 (119G)          ENERGY DEVELOPMENT CORP                                   108
2020    TRANSCO - FALFURRIAS TRANSPORT                                                                  1,235
2       FOREST - EUGENE ISLAND BLK 325          FOREST OIL CORP                                           347
2       VALERO - MONTE CHRISTO EXCHANG          VALERO TRANSMISSION LP                                    309
2273    ZILKHA - WEST CAMERON 53                                                                          926
2298    M W - WELCH DEHYDRATION                                                                           669
8029    COLUMBIA SHIP SHOAL BLK 247F                                                                      396

                                                                                                       15,728

0122    ESSEX-HAVERHILL SMS                     ESSEX COUNTY GAS CO                                    17,300       100 LBS
0138    ESSEX-WENHAM MASS                       ESSEX COUNTY GAS CO                                     4,100       100 LBS
0323    ESSEX-ESSEX MASS                        ESSEX COUNTY GAS CO                                       900       100 LBS
</TABLE>

                                       7
<PAGE>

<TABLE>
<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                      COUNTY          ST     ZONE  R/D    LEG
------------------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                          <C>             <C>     <C>    <C>  <C>
0578    PENN-NFG-ANDREWS SETTLEMENT SA          PENN YORK ENERGY CORPORATION                 POTTER          PA      04     D    300
0018    TGP - NORTHERN STORAGE INJECTI                                                       POTTER          PA      04     D    300

<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME              METER-TQ    Minimum Pressure
------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                    <C>           <C>
0578    PENN-NFG-ANDREWS SETTLEMENT SA          PENN YORK ENERGY CORPORATION            2,333         2,333
0018    TGP - NORTHERN STORAGE INJECTI                                                  8,354         8,354

                                                           Total Delivery TQ:          32,987        32,987
</TABLE>

NUMBER OF RECEIPT POINTS AFFECTED: 20
NUMBER OF DELIVERY POINTS AFFECTED: 5

THE SUM OF TRANSPORTER'S DELIVERIES TO SHIPPER FOR ALL TRANSPORTATION CONTRACTS
CONVERTED FROM FIRM SALES CANNOT ON ANY DAY EXCEED THE FOLLOWING QUANTITIES:

<TABLE>
<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                      COUNTY          ST     ZONE  R/D    LEG
------------------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                          <C>             <C>     <C>    <C>  <C>
0122    0 ESSEX-HAVERHILL SMS                   ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200
0138    0 ESSEX-WENHAM MASS                     ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200
        0 ESSEX-ESSEX MASS                      ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200
        0 PENN-NFG-ANDREWS SETTLEMENT SA        PENN YORK ENERGY CORPORATION                 POTTER          PA      04     D    300
10018   0 TGP - NORTHERN STORAGE INJECTI                                                     POTTER          PA      04     D    300

<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                 METER-TQ    Minimum Pressure
-------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                       <C>          <C>
0122    0 ESSEX-HAVERHILL SMS                   ESSEX COUNTY GAS CO                       17,300
0138    0 ESSEX-WENHAM MASS                     ESSEX COUNTY GAS CO                        4,100
        0 ESSEX-ESSEX MASS                      ESSEX COUNTY GAS CO                          900
        0 PENN-NFG-ANDREWS SETTLEMENT SA        PENN YORK ENERGY CORPORATION               2,333
10018   0 TGP - NORTHERN STORAGE INJECTI                                                   8,354
</TABLE>

THE SUM OF TRANSPORTER'S DELIVERIES TO SHIPPER FOR ALL TRANSPORTATION CONTRACTS
CONVERTED FROM FIRM SALES CANNOT EXCEED 4,100 DTH/DAY FOR THE FOLLOWING METERS.

<TABLE>
<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                      COUNTY          ST     ZONE  R/D    LEG
------------------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                          <C>             <C>     <C>    <C>  <C>
20138   0 ESSEX-WENHAM MASS                     ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200
20323   0 ESSEX-ESSEX 14ASS                     ESSEX COUNTY GAS CO                          ESSEX           MA      06     D    200

<CAPTION>
METER   METER NAME                              INTERCONNECT PARTY NAME                              METER-TQ    Minimum Pressure
------------------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                     <C>                                                    <C>          <C>
20138   0 ESSEX-WENHAM MASS                     ESSEX COUNTY GAS CO
20323   0 ESSEX-ESSEX 14ASS                     ESSEX COUNTY GAS CO
</TABLE>

METERS 060018 AND 070018 ARE FOR NOMINATION PURPOSES ONLY AND DO NOT DENOTE
CAPACITY AT THESE SPECIFIC POINTS.

Note: Exhibit "A" is a reflection of the contract and all amendments as of the
amendment effective date.

                                       8<PAGE>

                                                                  EXHIBIT 10.M.I

                           FOURTH AMENDMENT TO LEASE

        This FOURTH AMENDMENT TO LEASE ("Amendment") entered into as of
September 1, 1999, by and between FRANCIS J. PERRY, JR., FRANCIS J. PERRY III,
AND WILLIAM J. WALKER, JR. AS TRUSTEES OF ROSEMONT TRUST ("Trust") under
declaration of trust dated November 19, 1980, recorded with the NorfolK County
Registry of Deeds ("Registry") in Book 5856, Page 213, as amended by First
Amendment to Rosemont Trust dated December 22, 1986, recorded with Norfolk Deeds
in Book 7528, Page 525 and by Second Amendment to Declaration of Trust
Establishing Rosemont Trust dated March 31, 1995, recorded with Norfolk Deeds in
Book 11012, Page 206 ("Landlord"), as Landlord, and LTX CORPORATION, a
Massachusetts corporation ("Tenant"), as Tenant.

        REFERENCES AND RECITALS
        -----------------------

        Reference is made to the Third Amendment to Lease and Restatement of
Lease ("Lease") entered into April 29, 1982, by and between Landlord's
predecessors as trustees of the Trust as landlord and Tenant as Tenant. The
Lease amended, and restated in its entirety, a lease ("1980 Lease") originally
executed November 26, 1980 by and between Landlord's predecessors as trustees of
the Trust as Landlord and Tenant as Tenant, as the 1980 Lease had been
previously amended. Notice of the 1980 Lease was recorded with the Registry in
Book 5856, Page 228. Notice of the Lease was provided by a Second Amendment to
Notice of Lease recorded with the Registry in Book 5996, Page 564. All terms not
specifically defined in this Amendment have the meanings given to them in the
Lease.

        Landlord and Tenant now wish to amend the Lease in certain respects as
set forth below.

        FOR GOOD AND VALUABLE CONSIDERATION, THE RECEIPT AND SUFFICIENCY OF
WHICH IS ACKNOWLEDGED, LANDLORD AND TENANT HEREBY AMEND THE LEASE AS FOLLOWS:

        (1)  Section 1.1 of the Lease is amended by striking the words:
                                                    --------

             "Term: Twenty-five (25) years, as the same may be extended as
             provided in Article X hereof." and substituting in their place:
                                                ------------

             "Term: Ten (10) years, as the same may be extended as provided in
             Article X hereof, said ten-year term to commence on the Effective
             Date of the Fourth Amendment to this Lease (as that term is
             defined below).

<PAGE>

        (2)  Section 1.1 of the Lease is amended by striking the words:
                                                    --------

             "Fixed Rent:  $1,517,559 annually, payable monthly in installments
                           of $126,463.25, for the period commencing on the
                           Commencement Date and ending on the last day of the
                           fifth (5th) year thereafter. For the balance of the
                           Term, the Fixed Rent shall be the annual fair market
                           rental value as determined pursuant to Section 4.1 of
                           the Lease."

        and substituting in their place:
            ------------

             "Fixed Rent:  $1,633,135 annually, payable monthly in installments
                           of $136,094.58, for the period commencing on the
                           Effective Date of the Fourth Amendment to this Lease
                           (as that term is defined below) and ending on the
                           last day of the fifth (5th) year thereafter.
                           $1,800,636 annually, payable monthly in installments
                           of $150,053.00, for the period commencing on the
                           fifth anniversary of the Effective Date of the Fourth
                           Amendment to this Lease and ending on the last day of
                           the fifth (5th) year thereafter, the end of the ten
                           year term of this Lease. In the event the Tenant
                           exercises its option to extend the Term of this
                           Lease, all as provided in Article X hereof, the Fixed
                           Rent during any such Term shall be the annual fair
                           market rental value as determined pursuant to and
                           provided for in Article X of the Lease."

        (3)  Section 1.1 of the Lease is amended by adding, at the end of the
section, the following:

             "Effective Date of the Fourth Amendment to this Lease: December 1,
                                                                    ----------
1999."

        (4)  The following additional provision is added to the end of Section
             3.1:

             "As soon as practically possible, and in any event no later than
             September, 2000, Landlord will, at its expense, cause the roof of
             the building on the Premises to be replaced with a new roof at
             least substantially the same in quality as the roof originally
             installed on the building. The replacement roof will be warranted
             by the roof manufacturer or installer, with its standard form of
             warranty for such a roof, for a period of at least ten years
             following installation; Landlord will provide Tenant a document
             from the warrantying party that will recognize Tenant's rights to
             enjoy the benefit of the warranty."

                                       2

<PAGE>

     (5) Section 4.1 of the Lease, except for the first sentence thereof, is
deleted without substitution.

     (6)  Section 5.2.1 of the Lease is amended by deleting the last two
sentences and adding as a final sentence of Section 5.2.1 the following:
              ------

          "Landlord agrees not to withhold unreasonably consent to a sublease of
          all or any portion of the Premises provided that with respect to:

          (i) a sublease of less than 50% of the building area for a term or
              terms less than three years in duration, the proceeds of such
              subletting in excess of the Fixed Rent and Additional Rent are
              shared equally by Landlord and Tenant, and

         (ii) with respect to a subletting of 50% or more of the building area
              or a subletting of all or any portion of the Premises for a term
              of three years or more, that all or any portion of any proceeds
              derived from such subletting in excess of Fixed Rent and
              Additional Rent be paid to Landlord or Landlord may, at Landlord's
              option, elect to terminate this lease with respect to the space
              proposed to be sublet."

     (7) Article X of the Lease is deleted in its entirety and replaced with the
                                   -------
following:

                                   ARTICLE X

                          TENANT'S OPTIONS TO EXTEND

     10.1 Options to Extend.
          -----------------

     (a) Provided that, at the time of each such exercise, (i) this Lease is in
full force and effect, and (ii) no default by Tenant shall have occurred and be
continuing (either at the time of exercise or at the commencement of an Extended
Term), Tenant shall have the right and option to extend the Term of this Lease
for two (2) extended terms (collectively, the "Extended Terms") of five (5)
years each by giving written notice to Landlord not later than twelve (12)
months prior to the expiration date of the Initial Term with respect to the
first Extended Term, and not later than twelve (12) months prior to the
expiration date of the first Extended Term with respect to the second Extended
Term. The effective giving of such notice of extension by Tenant shall
automatically extend the Term of this Lease for the applicable Extended Term,
and no instrument of renewal or extension need be executed. In the event that
Tenant fails timely to give such notice to Landlord, this Lease shall
automatically terminate at the end of the Term then in effect, and Tenant shall
have no further option to extend the Term of this Lease. Each Extended Term
shall commence on the day immediately succeeding the
<PAGE>

expiration date of the Initial Term or the preceding Extended Term, as the case
may be, and shall end on the day immediately preceding the fifth anniversary of
the first day of such Extended Term. The Extended Terms shall be on all the
terms and conditions of this Lease, except: (i) during the Extended Terms,
Tenant shall have no further option to extend the Term, except as provided
herein during the first Extended Term with respect to the second Extended Term,
and (ii) the Fixed Rent for the Extended Terms shall be the Fair Market Rental
Value for the Premises as of the commencement of the Extended Term in question,
determined pursuant to paragraph (b) of this Section 10.1.

     (b)  Promptly after receiving Tenant's notice extending the Term of this
Lease pursuant to paragraph (a) above, Landlord shall provide Tenant with
Landlord's good faith estimate of the Fair Market Rental Value of the Premises
for the applicable Extended Term based upon rents being paid by tenants renewing
leases or entering into new leases for space of comparable size, type, use and
quality in the general vicinity of the Premises, including allowances and
concessions. If Tenant is unwilling to accept Landlord's estimate of Fair Market
Rental Value as set forth in Landlord's notice referred to above, and the
parties are unable to reach agreement hereon within thirty (30) days after the
delivery of such notice by Landlord, then either party may submit the
determination of the Fair Market Rental Value of the Premises to arbitration by
giving notice to the other party naming the initiating party's arbitrator.
Within fifteen (15) days after receiving the notice of initiation of
arbitration, the responding party shall appoint its own arbitrator by notifying
the initiating party of the responding party's arbitrator. If the second
arbitrator shall not have been so appointed within such fifteen (15) day period,
the Fair Market Rental Value of the Premises shall be determined by the
initiating party's arbitrator. If the second arbitrator shall have been so
appointed, the two arbitrators thus appointed shall, within fifteen (15) days
after the responding party's notice of appointment of the second arbitrator,
appoint a third arbitrator. If the two initial arbitrators are unable timely to
agree on the third arbitrator, then either may, on behalf of both, request such
appointment by the Boston office of JAMS/ENDISPUTE, or its successor, or, on its
failure, refusal or inability to act, by a court of competent jurisdiction.
Within fifteen (15) days after the appointment of the third arbitrator, the
three arbitrators shall determine the Fair Market Rental Value of the Premises
and give notice thereof to the parties hereto, and the arbitrators'
determination shall be binding upon the parties. In the event the three
appraisers are unable to agree upon the Fair Market Rental Value of the
Premises, then the average of the two of the three appraisals which are closest
to each other shall be deemed to be the Fair Market Rental Value of the
Premises. In no event shall the annual Fixed Rent to be paid during the first
Extended Term ever be less than the annual Fixed Rent payable during the final
year of the Term prior to extension. In no event shall the annual Fixed Rent to
be paid during the second Extended Term ever be less than the annual Fixed Rent
payable during the final year of the first Extended Term. All arbitrators shall
be appraisers or other qualified real estate professionals who are independent
from the parties and shall be Members of the Appraisal Institute who shall have
had at least ten (10) years commercial real estate experience in the greater
Boston area.

                                       4

<PAGE>

     10.2 No Option to Purchase. Tenant has no right or option whatsoever to
          ---------------------
purchase or otherwise acquire the Premises, any part thereof, or any interest
therein."

     Except as expressly amended in this Amendment, the Lease remains unamended,
and in full force and effect in accordance with its provisions.

     EXECUTED AS A MASSACHUSETTS INSTRUMENT UNDER SEAL AS OF THE DATE FIRST
WRITTEN ABOVE.

                                        LANDLORD

                                        /s/ Francis J. Perry
                                        ------------------------------
                                        Francis J. Perry, Trustee of
                                        Rosemont Trust, as aforesaid,
                                        and not individually

                                        /s/ William J. Walker, Jr.
                                        ------------------------------
                                        William J. Walker, Jr., Trustee of
                                        Rosemont Trust, as aforesaid,
                                        and not individually

                                        TENANT:

                                        LTX CORPORATION

                                        By:  /s/ David G. Facelli
                                        --------------------------------
                                        Name: David G. Facelli
                                        Title: VP/CFO

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00003-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00003-of-00352.parquet"}]]