LEASE AGREEMENT

By and Between

580 Winter Street Corp.,

LANDLORD

and

MFS Intelenet of Massachusetts, Inc.,
 
TENANT

October 20th, 1994

LEASE AGREEMENT

This LEASE made and entered into this 20th day of October, 1994, by and 
between 580 Winter Street Corp., a Massachusetts corporation having a usual 
place of business c/o WASA Management, 30 Federal Street, Boston, MA 02110 
(hereinafter the "Landlord"), and MFS Intelenet of Massachusetts, Inc., a 
Delaware corporation having a usual place of business at One Tower Lane, Suite 
1600, Oakbrook Terrace, IL 60181 (hereinafter the "Tenant").

1.      Premises and Exclusions: In consideration of the rents and covenants 
herein stipulated to be paid and performed by Tenant and upon the terms and 
conditions herein specified, Landlord hereby leases to Tenant, and Tenant
hereby 
leases from Landlord, the following-described premises:

A portion of the first floor of the building located at 580 Winter Street 
in Waltham, Massachusetts (hereinafter the "Building") consisting of 
approximately 15,252 square feet of rentable area and a portion of the roof 
consisting of approximately 2,500 usable square feet (hereinafter the 
"Premises") as shown on Exhibit "A" attached hereto, subject to and with the 
benefit of all easements, agreements, restrictions and encumbrances now of 
record, to the extent in force and applicable.  The Building, together with
the 
parcel of land on which the Building is located, may be referred to
hereinafter 
as the "Property".

The Premises exclude exterior faces of exterior walls, the common 
stairways and stairwells, fan rooms, electric and telephone closets, janitor 
closets, freight elevator vestibules, and pipes, ducts, conduits, wires and 
appurtenant fixtures serving other parts of the Building (exclusively or in 
common).

Tenant shall have, as appurtenant to the Premises, rights to use in common 
with others entitled thereto (subject to reasonable rules of general 
applicability to tenants of the Building from time to time made by Landlord of 
which Tenant is given notice): (a) the common lobbies and corridors of the 
Building, and the pipes, ducts, conduits, wires and appurtenant meters and 
equipment serving the Premises in common with others; (b) common walkways 
necessary to access the Building; (c) if the Premises include less than the 
entire rentable floor area of any floor, the common toilets and corridors on 
such floor and serving the Premises; and (d) eight (8) undesignated parking 
spaces in the rear parking lot (with the right to add up to seven additional 
undesignated. parking spaces upon written notice to Landlord) and one (1) 
loading dock, such parking spaces and loading dock to be in the location shown 
on Exhibit A, subject to rights of others, if any, to exclusive use of parking 
and loading areas, but which exclusive use of others will not interfere with
the rights and use of such parking spaces and loading dock herein granted to
Tenant.

Landlord reserves for the benefit of Landlord and other occupants of the 
Building, the right, from time to time, without unreasonable interference with 
Tenant's office use: (a) to install, use, maintain, repair, replace and
relocate for service to the Premises and other parts of the Building, or
either, pipes, ducts, conduits, wires and appurtenant fixtures, wherever
located in the Premises or Building provided the same are not located above,
below or through 
Tenant's switch facility; and (b) to alter or relocate any other common
facility 
provided same does not materially and adversely affect the operation of
Tenant's 
switch facility.  Installations, replacements and relocations referred to in 
clause (a) above shall be located to the extent practicable in the central
core area of the Building, above ceiling surfaces, below floor surfaces or
within perimeter walls of the Premises.

2.      Use: Throughout the Term (hereinafter defined) of this Lease, Tenant 
shall continuously use and occupy the Premises for general and executive 
offices, warehousing and the installation, operation and maintenance of 
telecommunications equipment and transmission facilities, including but not 
limited to, a switch facility and customer collocation provising equipment,
and 
other uses normally related thereto (the "Permitted Use") and for no other 
purpose.

Tenant at its sole expense shall comply with all laws, rules, orders and 
regulations of federal, state, county and municipal authorities and with any 
direction of any public officer or officers, pursuant to law, which will
impose 
any duty upon Landlord or Tenant with respect to or arising out of Tenant's
use 
or occupancy of the Premises.  If Tenant receives notice of any violation of 
law, ordiance, order or regulation applicable to the Premises, it shall give 
prompt notice thereof to the Landlord.

Tenant shall not injure, overload, deface or commit waste in the Premises, 
or any part of the Building, nor permit the occurrence of any nuisance therein 
or, unless otherwise permitted herein, the emission therefrom of any 
objectionable noise or odor, nor use or permit any use of the Premises which
is 
improper, offensive, contrary to law or ordinance or which is liable to render 
necessary any alterations or additions in the Building, nor obstruct in any 
manner any portion of the Building or appurtenant land.  Tenant may not,
without 
Landlord's prior written consent, install in the Premises any water fountains, 
refrigerators, sinks or cooking equipment, provided that Landlord's consent
will 
not be unreasonably withheld with respect to items designed for the
convenience 
of Tenant's employees and further provided that special venting or other
matters 
are not required in connection therewith.

3.      Term.  Subject to the terms, covenants, agreements and conditions 
contained herein, Tenant shall have and hold the Premises for an initial term 
(the "Term") of fifteen (15) years and six (6) months, commencing upon the
date 
of delivery of the Premises to Tenant after completion of Landlord's Pre-
Commencement Work pursuant to Section 7 hereof (the "Commencement Date").

Tenant shall be responsible for the payment of additional rent and all 
other charges hereunder beginning on the Commencement Date.  Tenant shall be 
responsible for the payment of Basic Annual Rent (hereinafter defined) on the 
Rent Commencement Date (hereinafter defined).  As used herein, the term
"lease year"    shall mean each twelve (12) month period during the 
Term,
commencing      on the Commencement Date.

3.1     Extension: So long as Tenant is not in default hereunder, and no
event has occurred which, with the passage of time, could ripen into 
default, Tenant shall have the option to extend the Term for two (2) extended 
terms of five (5) years each (the "Extended Terms").  The Extended Term(s)
shall 
commence immediately following the end of any then existing Term.  Tenant may 
exercise its option to extend for any Extended Term by giving written notice
to 
Landlord at any time during the then existing Term of the Lease, but no later 
than twelve (12) months prior to the end of the then existing Term.  All terms 
and conditions applicable during the Term shall apply during any Extended 
Term(s), except for Basic Annual Rent which shall be as provided below.  If 
Tenant fails to give such notice exercising its option for the Extended
Term(s) 
within the time provided above, time being of the essence, this Lease shall 
automatically expire at the end of the then existing Term (unless sooner 
terminated as provided herein).

4.      Basic Annual Rent: Security Deposit:

(a)     Tenant shall not be obliged to pay Basic Annual Rent for the first 
six (6) months of the first lease year of the Term, (ii) the first one (1)
month 
of the eleventh (11th) lease year of the Term, and (iii) the final two (2) 
months of the final year of the Term, as extended if applicable (collectively, 
the "Free Rent Period").  The day on which Basic Annual Rent shall be due
shall 
be known as the "Rent Commencement Date".

(b)     Tenant covenants to pay to Landlord, Basic Annual Rent as
follows:

Lease Years 1-10 - ($7.50 per square feet of rentable area)
- - $114,390.00 per annum, or $9,532.50 monthly; and

Lease Years 11-15.5 - ($9.50 per square feet of rentable
area) - $144,894.00 per annum, or $12,074.50 monthly.

Basic Annual Rent for the seventh month of the First Lease Year shall be 
payable on the execution of this Lease.

In the event of the commencement or termination of this Lease, other than 
on the first or last day of a calendar month, Basic Annual Rent, additional
rent 
and other charges shall be appropriately prorated for the portion of the month 
elapsed to the Commencement Date, or to and including the date of termination, 
as the case may be.

(c)     Tenant will pay the Basic Annual Rent, additional rent and all other 
charges due hereunder on the first day of each month in advance, without set-
off, counterclaim, deduction or demand, to Landlord at the address set forth 
below, or at such other place as is designated in writing from time to time by 
Landlord.

(d)     All payments of Basic Annual Rent, additional rent and all other 
charges due hereunder shall be made to the Landlord at c/o WASA Management, 30 
Federal Street, Boston, MA 02110, or such other address as Landlord may from 
time to time designate by notice to Tenant.

Landlord, may at the completion of Tenant's Work (as such term is defined 
in Section 7 hereof), measure the Premises.  Tenant's rentable area shall then 
be finally computed and notice thereof shall be provided to Tenant.  For the 
purpose of this Lease, Tenant's rentable area shall be the product of (i) the 
total usable area of the Premises excluding the portion of the Premises
located 
on the roof and (ii) 1.039.

4.1     Free Rent Restriction: This Lease provides for a Free Rent Period 
during which Tenant's liability for the payment of Basic Annual Rent at the
then 
normal monthly rate shall be suspended.  Tenant shall be credited with having 
paid all sums which would otherwise be due only if, at the end of the Term of 
the Lease, as it may have been extended hereunder, Tenant has fully,
faithfully, 
and punctually performed all of Tenant's obligations hereunder, including the 
payment of all additional rent and other charges (other than Basic Annual Rent 
during the Free Rent Period) and all other monetary obligations and Tenant
shall 
have, at the appointed time, surrendered the Premises in the physical
condition 
required by this Lease.  Tenant acknowledges that its right to receive credit 
for payment which would have otherwise been due for the Free Rent Period is 
absolutely conditioned upon Tenant's full, faithful and punctual performance
of 
its obligations under this Lease.  If Tenant defaults and does not cure within 
the applicable grace period, payments of Basic Annual Rent which would
otherwise 
have been due during the Free Rent Period shall immediately become due and 
payable in full and this Lease shall be enforced as if there were not such
Free 
Rent Period or other rent concessions.  In such case, Basic Annual Rent due
for 
the Free Rent Period shall be calculated based upon the full Basic Annual Rent 
payable under this Lease for such lease year.

4.2     Extended Term: If Tenant exercises its option to extend the Term of 
this Lease for any Extended Term, Tenant covenants to pay to Landlord, during 
such Extended Term of this Lease, Basic Annual Rent equal to fair market rent 
(for a five (5) year term determined as of the date which is twelve (12)
months 
prior to the end of the previously existing Term) for comparable space in 
buildings similar to the Building in the area of the City of Waltham in the 
vicinity of the Building, but in no event shall Basic Annual Rent for such 
Extended Term be less than the Basic Annual Rent for the immediately preceding 
lease year of the term (the "Basic Annual Rent Floor").  It is understood and 
agreed that fair market Basic Annual Rent for any Extended

Term, as determined in the manner hereinafter provided, need not be a 
single rate for the entire Extended Term, but rather may be stepped over the 
course of the Extended Term.

Landlord shall notify Tenant as to the proposed Basic Annual Rent for the 
Extended Term of this Lease at least ten (10) months prior to the end of the 
Term.  Landlord shall notify Tenant of Landlord's chosen appraiser together
with 
Landlord's notice as to Basic Annual Rent for the Extended Term proposed by 
Landlord.  If Tenant disputes the amount of Basic Annual Rent so established
by 
Landlord, Tenant shall either rescind its option to extend the Term or notify 
Landlord of Tenant's objection to said amount within thirty (30) days after
the 
receipt of Landlord's notice to Tenant, which notice shall be accompanied by
the 
name of one (1) appraiser if Tenant does not rescind its option.  Tenant's 
failure to notify Landlord of Tenant's rescission or objection shall
constitute 
Tenant's agreement to the Basic Annual Rent specified by Landlord.  If Tenant
so 
notifies Landlord of Tenant's objection, then the amount of Basic Annual Rent 
for each year of the Extended Term shall be decided by three (3) appraisers,
one 
(1) selected by Landlord, one (1) selected by Tenant, and one (1) selected by 
the first two (2) appraisers selected.  Each party shall pay for the appraiser 
selected by it and the cost of the third appraiser shall be divided equally 
between the parties.  In no event may any appraiser determine fair market rent 
to be less than the Basic Annual Rent Floor.

Each appraiser shall have at least ten (10) years experience in the 
management, ownership and/or appraisal of property similar to the Building in 
the City of Waltham.  If two (2) appraisers are able to agree upon the Basic 
Annual Rent for each year of the Extended Term, then the Basic Annual Rent
shall 
be as determined by said two (2) appraisers, but only if the determination of 
said two (2) appraisers is within ten percent (10%) of the determination of
the 
third appraiser for each year of the Extended Term.  If the foregoing
condition 
is not satisfied, or if no two (2) appraisers are able to agree upon Basic 
Annual Rent for each year of the Extended Term, the Basic Annual Rent for each 
year of the Extended Term shall be the average of the determination of all
three 
(3) appraisers, but only if the lowest determination is at least ninety
percent 
(90%) of the highest determination.  If this procedure cannot be followed 
because the lowest determination is not ninety percent (90%) of the highest 
determination, then the appraisers shall send a notice to Landlord and Tenant, 
setting forth their individual determinations, and the highest such 
determination for each year and the lowest such determination for each year 
shall be disregarded and the remaining determination for each year shall be 
deemed the Basic Annual Rent for each year of the Extended Term.

If any appraiser is not appointed as provided herein, either party may 
request that such appraiser be appointed by the President of the Boston Bar 
Association and the costs of any appraiser so appointed shall be equally
divided 
by Landlord and Tenant.

Basic Annual Rent for each Extended Term(s) -payable in equal monthly 
installments, in advance, on the first day of every month during each Extended 
Term(s).

5.      Operating Costs:

(a)     As used in this Section, these words and terms shall have the 
following meanings:

(i)     "Operating Costs" shall mean all costs incurred and expenditures 
paid by the Landlord in the operation and management, maintenance and repair
of 
the Property, including, without limitation, the Building, common areas, and
the 
land on which the Building is situated, exclusive of financing expenses, as 
determined by Landlord's accountant in accordance with generally accepted 
accounting principles consistently applied.  Subject to subsection (ii) below, 
Operating Costs include, without limitation, costs of security and janitorial 
service (including costs of materials and equipment); maintenance and repairs
to 
the Premises and the Property (including, without limitation, snow removal and 
landscaping); payments under all service contracts relating to the operation
and 
maintenance of the Property; management fees; wages, salaries, benefits,
payroll 
taxes and unemployment compensation insurance for employees of Landlord below 
the level of Building Supervisor or any contractor of Landlord engaged in the 
cleaning, operation, maintenance or security of the Property; insurance
relating 
to the Property; any capital expenditure (amortized, with interest, on such 
reasonable basis as Landlord shall determine) made by Landlord for the purpose 
of reducing other operating expenses or complying with any governmental 
requirement arising after the date hereof (collectively the "Permitted Capital 
Expenditures'); legal fees related to the management and operation of the 
Property; auditing expenses, payments other than Real Estate Taxes (as 
hereinafter defined) to the City of Waltham (including, but not limited to, 
water and sewer use charges, fire service fees and other user fees), supplies 
and all other expenses customarily incurred in connection with the operation
of 
first class retail/office buildings.

(ii)    "Operating Costs" shall not include the following:

1.      costs incurred in connection with the original construction of the 
Building or in connection with any major change in the Building, such as
adding 
or deleting floors;

2.      interest, principal, late charges, default fees, prepayment 
penalties or premiums on any debt owed by Landlord, including any mortgage
debt, 
and depreciation;

3.      costs of correcting defects in or inadequacy of the initial design 
or construction of the Building;

4.      expenses directly resulting from the negligence of the Landlord, its 
agents, servants or employees;

5.      legal fees, space planners fees, real estate brokers' leasing 
commissions and advertising expenses incurred in connection with the original 
development or original leasing of the Building or future leasing of the 
Building;

6.      costs for which Landlord is reimbursed by insurance by its carrier 
or Tenant's carrier or by anyone else;

7.      any bad debt loss, rent loss, or reserves for bad debts or rent 
loss;

8.      costs associated with the operation of the business of the 
partnership or corporation which constitutes Landlord, as the same are 
distinguished from the costs of operation of the Building, including
partnership 
or corporation accounting and legal matters, costs of defending any lawsuits 
with any mortgagee (except as the actions of Tenant may be the issue), costs
of 
selling, syndicating, financing, mortgaging or hypothecating any of Landlord's 
interest in the Building, costs (including attorney fees and costs of
settlement 
judgments and payments in lieu thereof) arising from claims, disputes or 
potential disputes in connection with potential or actual claims, litigation
or 
arbitrations respecting Landlord and/or the Building;

9.      the wages and benefits of any employee who does not devote 
substantially all of his or her time to the Building unless such wages and 
benefits are prorated to reflect time spent on operating and managing the 
Building vis-a-vis time spent on matters unrelated to operating and managing
the 
Building;

10.    fines, penalties and interest;

11.     amounts paid as ground rental by Landlord;

12.     costs of compliance with any handicap or other subsequent 
governmental code regulations, including ADA that are attributable to a 
particular tenant in the building other than Tenant;

13.     costs of compliance with applicable laws arising from the presence 
of hazardous materials or substances in or about the Building, or the site
upon 
which the Building is situated, including without limitation, hazardous 
substances in the ground water or soil and the removal of asbestos-containing 
materials; provided, however, that Tenant shall be liable and responsible for 
such costs if attributable to Tenant pursuant to Section 35 of the Lease;

14.     costs paid to Landlord or to affiliates of Landlord for services in 
the Building including management fees to the extent the same exceed or would 
exceed the costs for such services if rendered by unaffiliated third parties
on 
a competitive basis;

15.     any compensation paid to clerks, attendants or other persons in 
commercial concessions operated by Landlord or in any parking areas;

16.     rentals and other related expenses incurred in leasing air 
conditioning systems, elevators or other equipment ordinarily considered to be 
of a capital nature if purchased, except equipment not affixed to the Building 
which is used in providing janitorial or similar services;

17.     all items and services for which Tenant or anyone else reimburses 
Landlord;

18.     costs arising from Landlord's political or charitable contributions;

19.     costs arising from latent defects in the Building or improvements 
installed by Landlord;

20.     costs for which Landlord has been compensated by a management fee;

21.     Landlord's general corporate overhead and general and administrative 
expenses; and

22.     costs incurred by Landlord due to the violation by Landlord of the 
terms and conditions of any lease of space in the Building.

23.     capital expenditures, except the Permitted Capital Expenditures.

(iii)   "Operating Cost Statement" shall mean a statement in writing signed 
by Landlord, setting forth the actual Operating Costs incurred by Landlord for
a 
specified computation year pursuant to this Section.  Landlord shall use 
reasonable efforts to deliver the Operating Cost Statement to Tenant within 
ninety (90) days after the end of the computation year.

(b)     Tenant shall pay to Landlord, as additional rent for each calendar 
year, Tenant's proportionate share of Operating Costs.  Tenant's proportionate 
share of Operating Costs shall be 19.4%, determined by dividing 15,252, being 
the number of rentable square feet leased by Tenant, by 78,680, being the
number 
of rentable square feet in the Building.  Tenant's proportionate share of 
Operating Costs shall be subject to adjustment in the event the rentable
square 
footage leased by Tenant or the rentable square footage in the Building either 
increases or decreases.  Such amount shall be due and payable within thirty
(30) 
days following receipt by Tenant of the Operating Cost Statement for such
year.

Commencing on the first day of the first calendar month of the first lease 
year of the Term, and on the first day of each calendar month thereafter
during 
the Term of this Lease, Tenant shall pay to Landlord, as estimated payments of 
Tenant's proportionate share of Operating Costs for such calendar year, one-
twelfth (1/12) of the amount reasonably estimated in good faith by Landlord to 
be Tenant's proportionate share of Operating Costs for such year.  Tenant
shall 
have the right to review Landlord's estimate of Operating Costs.  Such
payments 
shall be credited to the sum finally determined to be payable for the calendar 
year pursuant to the Operating Cost Statement, with the excess estimated 
payments, if any, paid to Tenant within thirty (30) days after delivery of the 
Operating Cost Statement.

If this Lease shall commence or terminate other than on the first or last 
day of a calendar year, Tenant shall be liable for only that portion of its 
proportionate share of Operating Costs for such calendar year represented by a 
fraction, the numerator of which is the number of days of the Term, as it may
be 
extended hereunder, which falls within the calendar year and the denominator
of 
which is three hundred sixty-five (365).

Any obligations under this Section of Tenant which shall not have been 
paid at the termination or earlier expiration of the Term of this Lease shall 
survive such termination or earlier expiration and shall be paid when and as
the 
amount of the same shall be determined together with interest thereon at the 
rate set forth in Section 20(d).

Tenant shall have the right, at Tenant's expense, exercisable by written 
notice to Landlord within nine (9) months following receipt of the Operating 
Cost Statement for a specified computation year, to review Landlord's books
and 
records with respect to such Operating Cost Statement.

6.      Real Estate Taxes:

(a)     As used in this Section, these words and terms shall have the
following meanings:

(i)     "Real Estate Taxes" shall mean all payments for all taxes, 
assessments and betterments levied, assessed or imposed by any
governmental authority upon or against the Property or Building or payments in 
lieu thereof, including reasonable expenses, which shall include without 
limitation, fees of attorneys, appraisers and other consultants incurred in 
connection with any efforts to obtain abatements or reductions or to assure 
maintenance of Landlord's taxes for any tax fiscal year wholly or partially 
included in the Term.  If, at any time during the Term of this Lease, any tax
or 
excise on rents or other taxes, however described, are levied or assessed 
against Landlord with respect to the rent reserved hereunder, either wholly or 
partially in substitution for, or in addition to, real estate taxes assessed
or 
levied on the Property or Building, or payments in lieu thereof, such tax or 
excise on rents shall be included in Real Estate Taxes; however, Real Estate 
Taxes shall not include franchise, estate, inheritance, succession, capital 
levy, transfer, income or excess profits taxes assessed to Landlord.  Real 
Estate Taxes shall further not include interest, penalties, or late charges 
associated with any late payment of Real Estate Taxes by Landlord, unless
caused by Tenant.

(ii)    "Real Estate Tax Statement" shall mean a statement in writing signed 
by Landlord, setting forth the Real Estate Taxes paid by or to be paid for a 
specified computation period pursuant to this Section accompanied by a copy of 
the applicable tax bill.

(iii)   "Tax Year" shall mean the fiscal tax year of the City of Waltham, 
Massachusetts.

(b)     For each Tax Year during the Term of this Lease, Tenant shall
pay to Landlord, as additional rent, Tenant's proportionate share of Real 
Estate Taxes.  Tenant's proportionate share shall be 19.4%, determined by 
dividing 15,252, being the number of rentable square feet leased by Tenant, by 
78,680, being the number of rentable square feet in the Building.  Tenant's 
proportionate share of Real Estate Taxes shall be subject to adjustment in the 
event the rentable square footage leased by Tenant or the rentable square 
footage in the Building either increases or decreases.  Such amount shall be
due 
and payable fifteen (15) days following receipt by the Tenant of the Real
Estate 
Tax Statement for a tax period.

If this Lease shall commence or terminate other than on the first or last 
day of a Tax Year, Tenant shall be liable for only that portion of Real Estate 
Taxes in respect of such year represented by a fraction the numerator of which 
is the number of days of the Term which fall within the Tax Year and the 
denominator of which is three hundred sixty-five (365).

Any obligation under this Section of Tenant which shall not have been paid 
at the expiration of the Term of this Lease, as it may have been extended,
shall 
survive such expiration and shall be paid when and as the amount of the same 
shall be determined together with interest thereon at the rate set forth in 
Section 20(d) from the date the payment was first due to Landlord.

Tenant's proportionate share of Operating Costs and Real Estate Taxes 
shall be determined on the first day of the applicable calendar year for 
Operating Costs and the first day of the Tax Year for applicable Real Estate 
Taxes based on an application of the above-referenced fractions on such dates.

7.      Preparation for Occupancy:

(a)     Landlord's Work.  Prior to the Commencement Date, Landlord shall 
deliver the Premises in a "as is', "where is" condition except for Landlord's 
Pre-Commencement Work as described in Exhibit B attached hereto ("Landlord's 
Pre-Commencement Work").  Subject to delays due to governmental regulation, 
unusual scarcity of or inability to obtain labor or materials, labor 
difficulties, casualty, weather, or other causes reasonably beyond Landlord's 
control or attributable to Tenant's action or inaction, Landlord shall use 
reasonable speed and diligence in the construction of the work to be
undertaken 
by Landlord in the Premises, and shall use diligent efforts to deliver the 
Premises to Tenant within four (4) weeks after Landlord has obtained approval 
from the City of Waltham to undertake Landlord's Pre-Commencement Work. 
Subject 
to the delays specified in the preceding sentence, Landlord shall, at its own 
cost and expense, use reasonable speed and diligence to complete the work 
described in Exhibit B within six (6) months following the Commencement Date. 
("Landlord's Post Commencement Date Work").  Landlord's failure to complete 
Landlord's Pre-Commencement Work and/or Landlord's Post Commencement Date Work 
within the time periods specified herein, for any reason, shall not give rise
to 
any liability of Landlord hereunder, except for gross negligence or

wilful misconduct, shall not constitute a Landlord's default, shall not 
affect the validity of this Lease, and shall have no effect on the beginning
or 
end of the Term as otherwise determined hereunder or on Tenant's obligations 
associated therewith. (Landlord's Pre-Commencement Work and Landlord's Post 
Commencement Date Work shall hereinafter sometimes collectively be referred to 
as "Landlord's Work.")

Landlord's Post Commencement Date Work shall be treated as having been 
substantially completed on the date on which the work described in Exhibit "B" 
has been substantially completed except for minor items of construction work
and 
minor mechanical adjustments of equipment and fixtures which can be completed 
after occupancy has been taken without causing material interference with 
Tenant's use and occupancy of the Premises ("Punch List Items").

Landlord shall complete as soon as conditions practically permit all Punch 
List Items, and Tenant shall cooperate with Landlord in providing access as
may 
be required to complete such work in a normal manner.  Landlord shall permit 
Tenant access for installing Tenant's fixtures, communications systems,
computer 
equipment and appurtenances, and other equipment in portions of the Premises 
prior to substantial completion when it can be done without material 
interference with remaining work and with the maintenance of harmonious labor 
relations.

(b)     Tenant's Work.  Tenant will engage, at its expense (except as 
provided below), its own architect or engineer to produce plans and 
specifications ("Plans and Specifications") for the "build-out" of the
Premises 
required to prepare the Premises for the conduct of Tenant's business therein 
("Tenant's Work").  Without limiting the generality of the foregoing, Tenant's 
Work shall also include the construction of all (i) demising walls within or 
around the Premises; (ii) common bathrooms and the corridors leading thereto
and 
(iii) accessways leading to the Premises, excluding demising walls leading to 
the loading dock referred to in Section 1 above.  The Plans and Specifications 
shall set forth, among other things, (i) specifications for the use, operation 
and testing of Tenant's emergency generator and associated fuel tank and (ii) 
the items of Tenant's Work which Tenant shall be required to remove from the 
Premises at the expiration or earlier termination of this Lease ("Tenant's 
Removal Items").  Landlord shall provide, at Tenant's expense, temporary power 
to the Premises from existing sources during construction of Tenant's Work.

Prior to the commencement of Tenant's Work, Tenant shall deliver the Plans 
and Specifications to Landlord for its written approval, which approval shall 
not be unreasonably withheld or delayed.  Landlord shall respond to Tenant's 
request for approval of its Plans and Specifications within ten (10) business 
days after receipt thereof; the failure of Landlord to respond within said 
period shall constitute approval of the Plans and Specifications.  In the
event 
that Landlord shall not approve the Plans and Specifications, Landlord shall 
notify Tenant of its objections thereto.  Landlord and Tenant shall thereafter 
work cooperatively and in good faith to reach agreement upon mutually
acceptable 
Plans and Specifications.  Landlord shall not be deemed to be unreasonably 
withholding its consent to the Plans and Specifications if, among other
things:

(I)     the Plans and Specifications do not contain sufficient detail to 
enable Landlord to evaluate the effect including, without limitation, noise, 
vibration, odor and emissions, on the Building and Landlord's other tenants of 
Tenant's installation and testing of Tenant's emergency generator and
associated 
fuel tank (the "Generator Effect");

(ii)    the Generator Effect will, in Landlord's reasonable judgment, place 
the safety of the Building or Landlord's other tenants at risk; or

(iii)   Tenant's Work will, in Landlord's reasonable judgment, negatively 
effect the exterior appearance of the Building.

If, despite diligent and good faith efforts, Landlord and Tenant are 
unable to agree upon the Plans and Specifications within thirty (30) days
after 
Tenant has first submitted the Plans and Specifications to Landlord, then
either 
party shall have the right to terminate this Lease upon written notice to the 
other within five (5) days after the end of such thirty (30) day period,
without 
further recourse to either party.  If Tenant shall so exercise its right to 
terminate this Lease, then Tenant shall immediately reimburse Landlord for (i) 
the cost of Landlord's Work through the date of termination and (ii) all 
compensation paid to The Niles Company and CB Commercial Real Estate Group in 
connection with this Lease.

Submission of the Plans and Specifications to Landlord for approval shall 
be deemed a warranty by Tenant and Tenant's architect, jointly and severally, 
that all work described in the Plans and Specifications (i) complies with all 
applicable laws, regulations, building codes, and reasonable and prudent
design 
standards for a first-class building, (ii) does not in any manner affect the 
structural or exterior elements of the Building except as specifically
provided 
therein, and (iii) is in all respects compatible with the mechanical,
electrical 
and structural components and systems of the Building (including applicable 
loading limits).  Landlord's approval of the Plans and Specifications shall 
signify Landlord's consent to the work thereon only and shall not result in
any 
responsibility of Landlord concerning such work.

Tenant shall engage its own contractor, subject to Landlord's approval which 
approval shall not be unreasonably withheld or delayed, to perform Tenant's 
Work, at Tenant's sole cost and expense, and Tenant agrees to complete
Tenant's 
Work using reasonable speed and diligence.  Tenant shall not be responsible
for 
Landlord's own costs related to review, construction management or supervision 
fees, costs or expenses related to Tenant's Work.

All of Tenant's Work to the Premises shall conform to the approved Plans and 
Specifications and any changes thereto must be approved in writing by Landlord 
which approval shall not be unreasonably withheld or delayed.  Tenant's Work, 
together with all repairs required to be made by Tenant Pursuant to this
Lease, 
shall be made in a good and workmanlike manner Using first class materials and 
shall

comply with all applicable federal, state and local codes and ordinances.  
Tenant shall obtain all necessary permits from the appropriate governmental 
authorities, including, without limitation, any required Certificate of 
Occupancy.  The contractor, subcontractors and materialmen utilized by the 
Tenant to perform Tenant's Work shall be subject to Landlord's prior written 
approval which approval shall not be unreasonably withheld or delayed.  Tenant 
agrees not to create, incur or permit any lien or other obligation to exist 
against the Property or Landlord by reason of Tenant's Work and Tenant agrees
to 
hold Landlord harmless from and against any and all claims and demands by 
contractors or other third parties against the Property or Landlord relating
to 
or arising out of Tenant's Work.  Tenant will maintain insurance reasonably 
acceptable to Landlord during the performance of Tenant's Work, and copies of 
any such insurance policies will be provided to Landlord and any mortgagee of 
Landlord, naming Landlord and any such mortgagee of Landlord as additional 
insureds under such coverage.

Tenant's Work (except for Tenant's generator and associated fuel tank) shall
at 
once become part of the Property and belong to Landlord and Tenant shall have
no 
right or duty to remove same unless designated as Tenant's Removal Items.  Any 
damages so caused by the removal of any improvements made by Tenant, shall be 
immediately repaired by Tenant at its sole cost and expense.

(c)     Landlord makes no representation, express or implied, with respect to
this 
Lease (including, without limiting the generality of the foregoing, the 
suitability of the Premises for the Permitted Use or zoning thereof), except
as 
expressly contained herein.  Tenant has made its own investigation as to the
use 
of the Premises and will obtain any and all licenses or permits which would be 
required for the operation of Tenant's business.

(d)     All construction work required or permitted by this Lease, including 
Landlord's Work and Tenant's Work under this Section 7, shall be done in a
good 
and workmanlike manner and in compliance with all applicable laws, ordinances, 
regulations and orders and requirements of all public authorities and insurers 
of the Building.  Landlord, at its sole expense, shall procure all permits and 
licenses required by any governing authority having jurisdiction over the 
Building and the Premises to undertake and complete Landlord's Work under this 
Section 7, including building permits and any Certificate of Occupancy.  All
of 
Tenant's work shall be coordinated with any of Landlord's Work being performed 
by or for Landlord and in such manner as to maintain harmonious labor
relations.  
Each party may inspect the work of the other at reasonable times and shall 
promptly give notice of observed defects.  Each party authorizes the other to 
rely in connection with design and construction upon approval and other
actions 
on the party's behalf by any construction representative of the applicable 
party.

(e)     Except to the extent to which Tenant shall have given Landlord notice
of 
any matter in which Landlord has not performed Landlord's Work obligations
under 
this Section 7 not later than the end of the ninth full calendar month after
the 
Commencement Date (except for latent defects as to which the cut-off date
shall 
be the end of the twelfth full calendar month after the Commencement Date), 
Tenant shall be deemed conclusively to have approved Landlord's Work and shall 
have no

claim that Landlord has failed to per-form any of Landlord's obligations under 
this Section 7. Landlord agrees to correct or repair, at its expense. items 
which are then incomplete or do not conform to Landlord's Work contemplated in 
Exhibit B and as to which. in either case, Tenant shall have given notice to 
Landlord, as aforesaid.

8.      Improvements and Alterations:

(a)     During the Term of this Lease and following completion of Tenant's
Work, 
Tenant, at its own expense, may make non-structural alterations, additions and 
improvements (including, without limitation, interior painting and decorating) 
to the interior of the Premises which are necessary or appropriate for the 
conduct of Tenant's business with Landlord's prior written consent and in 
accordance with detailed working drawings and specifications describing such 
work which have been submitted in advance to, and approved in writing by, 
Landlord and with a contractor approved by Landlord.  Landlord's consent to
such 
alterations and approval of Tenant's contractor shall not be unreasonably 
withheld or delayed.  During the Term of this Lease, Tenant, at Tenant's own 
expense, may alter the existing curtain wall on any of the facades of the 
Premises to install louvers for additional outside air and/or exhaust air, at 
Tenant's option, but subject to Landlord's prior written consent (such consent 
not to be unreasonably withheld) and in accordance with detailed working 
drawings and specifications which have been submitted in advance to and
approved 
in writing by Landlord.  Tenant shall pay all costs of preparing plans,
drawings 
and specifications.  Such alterations, additions and improvements
(specifically 
excluding movable personal property installed by Tenant) are hereinafter 
collectively called the "Improvements".  All the Improvements, whether placed
in 
or attached to or made part of the Premises prior to or during the Term of
this 
Lease, shall become and be Landlord's property and, unless Landlord otherwise 
elects, shall be and remain part of the Premises as of the expiration or
earlier 
termination of the Lease.  Landlord shall notify Tenant in writing at the time 
Landlord approves Tenant's plans for Improvements of its election to require 
Tenant to remove any or all of its Improvements upon the expiration or earlier 
termination of this Lease.  Construction of the Improvements shall be
performed 
diligently and in a good and workmanlike manner and shall be expeditiously 
completed in compliance with all laws, ordinances, orders, rules, regulations 
and requirements.  All work done in connection with the Improvements shall 
comply with all requirements of insurance policies maintained by Landlord and 
Tenant.  Tenant, at its expense, shall procure all permits and licenses
required 
by any governing authority having jurisdiction over the Premises and the 
business to be conducted in the Premises.  Tenant shall promptly pay all costs 
and expenses of the Improvements and shall furnish indemnification bonds
against 
performance, liens, costs, damages and expenses in forms and amounts
reasonably 
satisfactory to Landlord, in connection with all alterations and Improvements. 

At the expiration or earlier termination of this Lease, Tenant shall remove
all 
of this personal property other than the Improvements, and, at the option of 
Landlord, Tenant shall remove any or all of the Improvements.  If Landlord 
elects to have Tenant remove the Improvements, Landlord shall not require 
removal of pipes, wires and the like from walls, ceilings or floors provided 
that Tenant properly cuts, caps and disconnects such pipes and wires and seals 
them off in a safe and lawful manner flush with the applicable wall, floor or 
ceiling and redecorates the area consistent with the remainder of the
Premises.  
Tenant shall maintain the

Improvements in a first class manner during the Term -of the Lease, as
extended, 
and shall be responsible for any and all damages to the Premises, the
fixtures, 
appurtenances and equipment of Landlord or the Building caused by the 
installation, malfunction or removal of the Improvements or Tenant's Property
as 
defined in Section 9 below.

(b)     In order to protect the historical and architectural integrity and 
appearance of the Building, Tenant shall not install any signs on the exterior 
of the Building or Premises or in the interior of the Premises if visible from 
the exterior of the Premises except as permitted by this paragraph or as 
approved in the Plans and Specifications.  All signs or lettering, if any, 
visible from the exterior of the Building or from the lobby, public corridors
or 
in any other common area or public place must be submitted by Tenant to
Landlord 
for prior written approval of the size, color, design, and location of such 
signs or lettering before installation.  Tenant may hang its own window blinds 
or curtains in the Premises subject to Landlord's prior written approval.

9.      Property of Tenant: Subject to the provisions of this Section 9,
Tenant 
may place fixtures, equipment, supplies and the like ("Tenant's Property") in 
the Premises.  Upon the expiration or sooner termination of this Lease, Tenant 
shall remove Tenant's Property and restore the Premises to its condition prior 
to installation of Tenant's Property ordinary wear and tear and loss by
insured 
casualty or condemnation excepted.  Tenant shall not place a load upon any
floor 
of the Premises exceeding the floor load per square foot area which such floor 
was designed to carry and which is allowed by law.  Machines and mechanical 
equipment and Tenant's other personal property shall be placed and maintained
by 
Tenant, at its expense, in settings sufficient to absorb and prevent
vibration, 
noise and annoyance and without overloading the electrical service available
to 
the Premises or to the Building.  Tenant covenants and agrees that all
Tenant's 
Property of every kind, nature and description which may be in or upon the 
Premises or Building, in the public corridors, or on the sidewalks, area ways 
and approaches adjacent thereto, during the Term and any movement of Tenant's 
Property, shall be at the sole risk and hazard of Tenant, and Tenant hereby 
indemnifies and agrees to save Landlord harmless from and against any
liability, 
loss, injury, claim or suit resulting directly or indirectly therefrom.

10.     Maintenance and Repair:

(a)     Tenant shall, at its sole cost and expense, maintain (i) the Premises, 
(ii) the common bathrooms and the corridors leading thereto, and (iii) the 
accessways leading to the Premises, (items (ii) and (iii) are referred to
herein 
as "Maintenance Areas'), in good order, condition and repair and shall make
all 
foreseen and unforeseen and ordinary and extraordinary changes and repairs 
required to keep the Premises and the Maintenance Areas in good repair and 
condition including, without limitation, repairs to vents, ducts, wires, fans, 
outlets, doors, locks, hardware, utility lines and facilities exclusively 
servicing the Premises and the Maintenance Areas, installations and equipment
on 
the roof installed by Tenant, electrical, plumbing and HVAC equipment 
exclusively serving the Premises and the Maintenance Areas, flooring, carpets, 
walls, ceilings, fixtures and exterior and interior

glass in the Premises and the Maintenance Areas and structural portions of the 
Building (including the roof) constructed or modified by or at the request of 
Tenant.  Tenant shall wash any dishes and perform any cleaning necessary to 
maintain the Premises and the Maintenance Areas in a clean and sanitary 
condition, free of all vermin, waste and fire hazards.  Tenant, at its own 
expense, shall supply and maintain all light bulbs, tubes, light fixtures, 
globes and switches or similar devices for lighting the Premises and the 
Maintenance Areas.

(b)     Except as provided in (a) above, Landlord shall (D keep the roof,
exterior 
walls and all structural portions of the Building so long as the same are not 
affected by Tenant's Work, and the plumbing lines and sewers, electrical
systems 
and utility service lines furnished by Landlord in good and serviceable 
condition and repair (except for any repair or replacement occasioned by any 
willful or negligent act or omission of Tenant, its servants, agents,
customers, 
contractors, employees or licensees) and provided further that Landlord shall 
not be obliged to repair any equipment or facilities serving the Premises
only; 
(ii) keep sidewalks, parking and landscape areas, common corridors, stairways, 
mechanical and electrical systems serving occupants of the Building other than 
Tenant (it being understood that Landlord shall not be obliged to repair any 
equipment or facilities exposed in the Premises or the Maintenance Areas or 
serving the Premises and the Maintenance Areas only), and all other public 
portions of the Building in serviceable repair and in a reasonably clean and 
safe condition and make repairs to all pipes, ducts, conduits, wires and 
appurtenant fixtures which run through Tenant's Premises but service other 
tenants, but not Tenant; and (iii) comply with applicable governmental rules, 
regulations, laws and ordinances affecting the Building, unless the violation
is 
caused by Tenant or Tenant's use of the Premises or Tenant's willful or 
negligent act or omission, in which case, compliance shall be at the expense
of 
the Tenant.  Landlord reserves the right to interrupt, curtail, stop and
suspend 
the furnishing of any services and the operation of the plumbing, electrical, 
heating, ventilating and air-conditioning system when necessary by reason of 
accident or emergency or for repairs, alterations, replacements or
improvements 
which may become necessary or when it cannot secure supplies or labor, or by 
reason of any other cause beyond its control, without liability or any
abatement 
of Basic Annual Rent, additional rent or other charges being due thereby.  If, 
due to causes within Landlord's reasonable control, services to the Premises
are 
interrupted or the operation of the plumbing, electrical or HVAC system is 
suspended for a period exceeding five (5) consecutive business days and such 
interruption or suspension renders all or a portion of the Premises unusable
for 
the Permitted Use, Tenant shall receive an equitable abatement of Rent for the 
period commencing on the sixth (6th) consecutive business ,day and ending on
the 
date such service is restored.

(c)     In the event Landlord fails to commence to repair a roof or ceiling
leak 
or other similar problem within twenty-four (24) hours following receipt of 
written notice from Tenant (which notice may be delivered by hand and then
given 
as set forth in Section 24), and diligently prosecute such repair to
completion, 
Tenant may, subject to the following conditions, cause the necessary repairs
to 
be performed at Landlord's expense.  With respect to Tenant's exercise of self 
help, the following shall apply: (i) Tenant may exercise such self help rights 
only in the event of an emergency wherein there exists an imminent-threat of 
damage or harm to persons or

property or cessation of operation of Tenant's switch facility; (ii) if Tenant 
elects to exercise its self help rights as set forth above, Tenant shall cure 
such defects as may be necessary to abate the emergency, even if such cure is 
temporary in nature, such that Landlord shall thereafter have the opportunity
to 
exercise a permanent cure; and (iii) Tenant agrees that the performance of any 
self help rights shall be limited to reasonable and competitive amounts.

11.     Services:

(a)     The Landlord shall provide:

(i)     Access to the Premises twenty-four (24) hours per day, 365 days per
year; 
provided, however, that outside normal business hours access shall be under 
conditions which will insure the security of the Building.

(ii)    Removal of snow and ice from the entry to and sidewalks of the
Building.

(b)     Landlord shall provide and maintain adequate connections with the
local 
water supply and sewerage systems.  Tenant shall install separate meters for 
Tenant's electrical and gas service and shall pay the cost of such meters and 
connections and shall pay the utility company directly for all fuel,
electrical, 
gas and other utilities (other than water) used by Tenant on the Premises and 
the Maintenance Areas.  With respect to water charges, Tenant shall pay
Landlord 
directly for Tenant's Share of the total amounts for the same within 30 days 
after billing by Landlord.  Upon request by Tenant, Landlord shall provide 
reasonable evidence indicating that all such charges for water are based upon 
compatible uses for all tenants in the Building.  Landlord agrees that, if any 
tenant of the Building (including Tenant) uses a disproportionate amount of 
water because of the specific nature of such tenant's business, Tenant's Share 
shall be equitably adjusted accordingly.

12.     Inspection: Landlord and its authorized representatives shall have the 
right, at all reasonable times and upon reasonable advance notice, to enter
the 
Premises to inspect the same (and at all times during an emergency), to make 
repairs or replacements therein as required by this Lease, to exhibit the 
Premises to prospective tenants, lenders or others; provided, however, that 
Landlord shall use all reasonable effort not to unduly disturb the Tenant's
use 
and occupancy.  Landlord shall not be liable to Tenant in any manner for any 
expense, loss or damage occurring by reason of the aforesaid entries, nor
shall 
the exercise of any such right be deemed an eviction or disturbance of
Tenant's 
use or possession.

13.     Casualty:

(a)     If the Premises, or any part thereof, shall be damaged by fire or
other 
casualty, Tenant shall give prompt notice to Landlord.  Upon receipt of such 
notice, Landlord (except as provided in subparagraph (b), (b)(i), (b)(ii), and 
(b)(iii)

below), shall proceed with reasonable diligence, and at its expense (but only
to 
the extent of insurance proceeds recovered or recoverable and made available
to 
Landlord by any mortgagee of the Building), to cause such damage to be
repaired 
and restored as nearly as possible to the condition in which they were 
immediately prior to the casualty.  All repairs to and replacements of
Tenant's 
Work, Tenant's Property and Improvements as defined in Section 8 shall be made 
by and at the expense of Tenant.

(b)     If the Premises, or any part thereof, shall have been rendered unfit
for 
use and occupation hereunder by reason of such damage, the Basic Annual Rent,
or 
a just and proportionate part thereof, according to the nature and extent to 
which the Premises shall have been so rendered untenantable, shall be
suspended 
or abated until the Premises (except Tenant's Work, the Improvements and 
Tenant's Property which are to be repaired by or at the expense of Tenant), 
shall have been restored as nearly as practicable to the condition in which
they 
were immediately prior to such fire or other casualty, provided that
restoration 
can be completed in accordance with applicable laws and regulations; provided, 
however that notwithstanding the foregoing, Tenant shall not be entitled to an 
abatement if the damage is by Tenant's Property and Improvements including, 
without limitation, any fuel tank or generator.  Landlord shall not be liable 
for delays in the making of any such repairs which are due to governmental 
regulations, casualties and strikes, unavailability of labor and materials,
and 
other causes beyond the control of Landlord, nor shall Landlord be liable for 
any inconvenience or annoyance to Tenant or injury to the business of Tenant 
resulting from reasonable delays in repairing such damage.  If the Premises
are 
damaged by fire or other casualty and said Premises shall not have been
restored 
to substantially the same condition which they were in prior to such fire or 
other casualty within one hundred eighty (180) days after such fire or other 
casualty or are not capable of being so restored, as reasonably determined- by 
an independent engineer selected by Landlord, then Tenant may terminate this 
Lease by notice to Landlord within fifteen (15) days after the end of said one 
hundred eighty (180) day period, without further recourse to either party.

(b)(i) If more than twenty-five percent (25%) of the Building is damaged by
such 
fire or other casualty, whether or not the Premises shall have been damaged by 
such fire or other casualty, or (ii) if more than fifty percent (50%) of the 
Premises is damaged by fire or other casualty, or (iii) if restoration cannot
be 
achieved on account of inadequate insurance proceeds, governmental
restrictions 
or otherwise, then this Lease and the Term hereof may be terminated at the 
election of Landlord by giving written notice of termination to the Tenant 
within sixty (60) days following such fire or other casualty, the termination 
date being specified in such notice as a date not less than thirty (30) days 
after the day on which such termination notice is given.  In the event of any 
such termination, this Lease and the Term hereof shall expire as of such 
effective termination date and the Basic Annual Rent shall be apportioned as
of 
such date.

14.     Condemnation - Eminent Domain:

(a)     If the Property, or any material part thereof, shall be taken or 
appropriated by eminent domain or shall be condemned for any public or quasi-
public use, or by reason of any transfer of all or any material part of the 
Building, or any

interest therein made in avoidance of such a taking or 'appropriation, or (by 
virtue of any taking, appropriation or condemnation) shall suffer any damage 
(direct, indirect or consequential) for which Landlord or Tenant shall be 
entitled to compensation, then (and in any such event) this Lease and the Term 
hereof may be terminated at the election of Landlord by giving a written
notice 
of termination to the Tenant within sixty (60) days following the date on
which 
Landlord shall have received notice of a taking, appropriation or
condemnation, 
or shall have effected such transfer.

If the entire Premises, or a portion thereof shall be so taken, appropriated, 
condemned or transferred, such that Tenant shall be precluded from effectively 
utilizing the Premises for its intended purpose, then (and in such event) this 
Lease and the Term hereof may be terminated at the election of Tenant by
giving 
a written notice of termination to Landlord within sixty (60) days following
the 
date on which Tenant shall have received notice of a taking, appropriation, 
condemnation, or on which Landlord shall have transferred such property.

Upon the giving of any such notice of termination by either Landlord or
Tenant, 
this Lease and the Term hereof shall terminate as of the date on which
Landlord 
or Tenant, as the case may be, shall be required to vacate any portion of the 
area so taken, appropriated or condemned or shall be deprived of the means of 
access thereto, provided, however, that Landlord in its notice of termination 
may elect to terminate this Lease and the Term hereof retroactively as of the 
date on which such taking, appropriation or condemnation became legally 
effective.  In the event of such termination, this Lease and the Term hereof 
shall expire as of such effective termination date and the Basic Annual Rent 
shall be apportioned as of such date.

(b)     If neither party elects to terminate this Lease and the Term hereof, 
Landlord shall, with reasonable diligence and at its expense (but only to the 
extent of the taking award recovered or recoverable and made available to 
Landlord by any mortgagees of the Building), restore the remainder of the 
Premises (but not the Improvements or any of Tenant's Property), as nearly as 
practicable to the condition thereof prior to such taking, appropriation or 
condemnation, in which event the Basic Annual Rent shall be adjusted in a
manner 
such that (i) a just proportion of the Basic Annual Rent, according to the 
nature and extent of the taking, appropriation or condemnation and the
resulting 
permanent injury to the Premises shall be permanently abated, and (ii) a just 
proportion of the remainder of the Basic Annual Rent, according to the nature 
and extent of the taking, appropriation or condemnation and the resultant
injury 
sustained by the Premises, shall be abated until what remains of the Premises 
(other than Tenant's Work, Improvements or any of Tenant's Property) shall
have 
been restored as fully as practicable for permanent use and occupation by
Tenant 
hereunder.  Landlord shall not be liable for any delays in such restoration 
which are due to governmental regulations, casualties, strikes, unavailability 
of labor or materials, or other causes beyond Landlord's control nor shall 
Landlord be liable for any inconvenience or annoyance to Tenant or injury to
the 
business of Tenant resulting from reasonable delays in such restoration.

Landlord expressly reserves to Landlord and Tenant hereby assigns to Landlord 
all rights to compensation and damages created, accrued or accruing by reason
of 
any taking, appropriation or condemnation, except for compensation

relating to Tenant's Property and for moving expenses, provided the same are 
separately awarded to Tenant without reduction of Landlord's award.

15.     Injury and Damage: Landlord shall not be liable for any injury or
damages 
to persons or property resulting from fire, explosion, falling plaster, steam, 
gas, electricity, electrical disturbance, water, rain or snow or leaks from
any 
part of the Building or from the pipes, appliances or plumbing works or from
the 
roof, street or subsurface or from any other place or by dampness or by any 
other cause of whatever nature, unless caused by or due to the act, omission, 
fault, negligence or misconduct of Landlord, or its agents, servants or 
employees; nor shall Landlord, its agents, servants or employees be liable for 
any such damage caused by other tenants or persons on the Property or caused
by 
construction operations of any private, public or quasi-public person; nor
shall 
Landlord be liable for any latent defect in the Premises or in the Building.

16.     Indemnification: Tenant hereby indemnifies and covenants to save
Landlord 
harmless from and against any and all claims, liabilities or penalties
asserted 
by or on behalf of any person, firm, corporation or public authority:

(i)     on account of or based upon any injury to person, or loss of or damage
to 
property, sustained or occurring on the Premises on account of or based upon
the 
act, omission, fault, negligence or misconduct of any person other than
Landlord 
or its servants, agents or employees;

(ii)    on account of or based upon any injury to persons, or loss of or
damage to 
property, sustained or occurring in or about the Property and other than on
the 
Premises (and, in particular, without limiting the generality of the
foregoing, 
on or about the elevators, stairways, public corridors, sidewalks, parking 
areas, concourses, arcades, approaches, area ways, roof or other
appurtenances and facilities used in connection with the Building or the 
Premises) arising out of the use and occupancy of the Building or the Premises 
by the Tenant or by any other person claiming by, through or under Tenant, and 
caused by the act, omission, fault, negligence or misconduct of Tenant or its 
servants, agents or employees, and in addition to and not in limitation of the 
foregoing subdivision (i); and

(iii)   on account of or based upon (including monies due on account of) any
work 
or thing whatsoever done (other than by Landlord or its contractors, or agents 
or employees of either) on the Premises during the Term and during the period
of 
time, if

any, prior to the Commencement Date when Tenant may have been given access to 
the Premises;

and, in respect of any of the foregoing, from and against all costs, expenses 
(including, without limitation, reasonable attorney's fees) and liabilities 
incurred in or in connection with any such claim, or any action or proceeding 
brought thereon.  If any action or proceeding be brought against Landlord by 
reason of any such claim, Tenant upon notice from Landlord shall at Tenant's 
expense resist and defend -such action or proceeding and employ counsel 
therefore reasonably satisfactory to Landlord, it being agreed that such
counsel 
as may act for insurance underwriters of Tenant engaged in such defense shall
be 
deemed satisfactory.

17.     Insurance:

(a)     Tenant covenants and agrees that from and after the date of delivery
of 
the Premises from Landlord to Tenant, and during the Term of this Lease,
Tenant 
will carry and maintain, at its sole cost and expense, the form of insurance 
hereinafter provided for:

(i)     Tenant shall keep in full force and effect Comprehensive General
Liability 
Insurance including Blanket Contractual, Personal Injury, Broad Form Property 
Damage, Products Liability, Completed Operations, Fire Legal Liability and 
Owned, Non-owned and Hired automobile coverages, naming Landlord and Tenant
and 
any designee of Landlord, as insured, with minimum limits of $1,000,000 for 
property damage, $1,000,000 for injury or death of one person and $3,000,000
for 
injury or death of more than one person in a single accident and from time to 
time thereafter shall not be less than such higher amounts as may reasonably
be 
required by Landlord for any and all claims for injury or damage to persons or 
property or for the loss of life or of property occurring upon, in or about
the 
Premises and the public portions of the Building used by Tenant, its
employees, 
agents, contractors, customers and invitees.  Tenant shall deposit a policy or 
policies of such insurance, or an approved certificate thereof issued by duly 
authorized agents or the carriers in question, with Landlord, at least ten
(10) 
days before the
Commencement Date and renewals of same and at least thirty (30) days prior to 
the expiration of any existing policies.  All such policies must provide that 
Landlord and any additional insured be provided with thirty (30) days prior 
written notice of cancellation, reduction, or material change by the insurer.

(ii)    Tenant shall keep in full force and effect All Risk insurance
including 
sprinkler leakage and floor and earthquake (if floor and earthquake exposure 
exists) and vandalism and malicious

mischief on a 100% replacement cost basis covering all contents, pictures and 
improvements.  Tenant shall deposit a policy or policies of such insurance, or 
an approved certificate thereof with Landlord, providing Landlord within
thirty 
(30) days notice of cancellation, reduction, or material change by the
insurer.

(iii)   Tenant shall keep in full force and effect Workers' Compensation
insurance 
as required by law and Employers' Liability coverage for a minimum of $100,000 
per occurrence.

(iv)    Tenant covenants to comply with any and all rules and regulations 
applicable to the Premises issued by the Board of Fire Underwriters or by any 
other body hereinafter constituted exercising similar functions and insurance 
companies writing policies covering the Premises.  Tenant shall pay all costs, 
expenses, claims, fines, penalties and damages imposed because of failure of 
Tenant to comply with this subsection (iv) and agrees to indemnify Landlord
from 
all liability with reference thereto.  Tenant shall, at its own cost and 
expense, procure and maintain each and every permit, license, certificate or 
other authorization and any renewals, extension or continuances of the same 
required in connection with lawful and proper use of the Premises for Tenant's 
business.

(b)     Tenant will not do, or omit to do, or keep anything in, upon or about
the 
Premises, the Building or any adjacent areas which may prevent the obtaining
of 
any fire, liability or other insurance upon or Written in connection with the 
Premises, the Building or such adjacent areas or which may make any such 
insurance void or voidable or otherwise invalidate the obligations of the 
insurer contained therein, or which may create any extra premiums or increase 
the rate of any such insurance over that normally applicable to office
buildings 
in the City of Waltham.  Tenant agrees to pay to Landlord, upon demand, the 
amount of any extra premiums or any increase in the rate of such insurance
which 
results from Tenant's use of the Premises, whether or not Landlord has
consented 
to such use.  In the event that the installation of Tenant's emergency
generator 
and associated fuel tank shall result in an increase in the rate of Landlord's 
insurance, than Tenant shall pay the amount of any such increase in insurance 
premium and such installation shall not give rise to an event of default 
hereunder.  If Tenant installs any electrical equipment in the Premises,
Tenant 
shall, at its expense, make whatever changes are necessary to comply with the 
requirements of the insurance underwriter or governmental authorities having 
jurisdiction, but such changes shall only be made in accordance with the 
provisions of this Lease.

(c)     Landlord agrees to maintain in force during the Term an all risk
property 
policy with 100% full replacement cost coverage.

18.     Waiver of Subrogation:

(a)     Tenant and Landlord covenant that with respect to all fire or extended 
coverage insurance carried by Tenant and Landlord in connection with the 
Premises or the Building, whether or not such insurance is required by the
terms 
of this Lease, such insurance shall provide for the waiver by the insurance 
carrier of any subrogation rights against the other party, its agents,
servants 
and employees under such party's insurance policies.

(b)     Notwithstanding any other provision of this Lease, (i) Landlord shall
not 
be liable to Tenant for any loss or damage, whether or not such loss or damage 
is caused by the negligence of Landlord, its agents, servants or employees, to 
the extent that such loss or damage is covered by valid and enforceable 
insurance carried by Tenant and containing subrogation waiver provisions 
pursuant to paragraph (a); and (ii) Tenant shall not be liable to Landlord for 
any loss or damage, whether or not such loss or damage is caused by the 
negligence of Tenant or its agents, servants or employees, to the extent that 
such loss or damage is covered by valid and enforceable insurance carried by 
Landlord and containing subrogation waiver provisions pursuant to paragraph
(a).

19.     Assignment, Mortgaging, Subletting:

(a)     Tenant covenants and agrees that neither this Lease, nor the Term, nor
the 
estate hereby granted, nor any interest herein or therein, will be assigned, 
mortgaged, pledged, encumbered or otherwise transferred, and that neither the 
Premises, nor any part thereof, will be encumbered in any manner by reason of 
any act or omission of Tenant, or used or occupied, or permitted to be used or 
occupied, by anyone other than Tenant and its employees, or for any use or 
purpose other than as above stated, or be sublet, or offered or advertised for 
subletting, without in each case, Landlord's prior written consent. 
Assignment 
shall include, without limitation, any transfer of the Tenant's interest in
the 
Lease by operation of law, merger or consolidation of the Tenant into any
other 
firm or corporation, and the transfer or sale of a controlling interest in 
Tenant, whether by sale of its capital stock or otherwise.  It is expressly 
understood and agreed that such consent may be withheld in Landlord's sole and 
absolute discretion; provided, however, Landlord's consent to a proposed 
assignment or subleasing shall not be unreasonably withheld or delayed.  
Landlord shall not be deemed to be unreasonably withholding its consent to
such 
a proposed assignment or subleasing if:

(a)     the proposed assignee or subtenant is not of a character consistent
with 
Tenant's use or the operation of a first-class office/retail building; or

(b)     the proposed assignee or subtenant is not of good character and 
reputation; or

(c)     the proposed assignee or subtenant does not possess adequate financial 
capability to perform the Tenant obligations as and when due or required; or

(d)     the proposed assignee or subtenant proposes to use the Premises (or
any 
part thereof) for a purpose other than the purpose for which the Premises may
be 
used as set forth in Section 2 hereof-, or

(e)     the character of the business to be conducted or the proposed use of
the 
Premises by the proposed assignee or subtenant shall (i) be likely to increase 
operating expenses for the Property beyond that which Landlord now incurs for 
use by Tenant, or (ii) violate or be likely to violate any provisions or 
restrictions contained herein relating to the use or occupancy of the
Premises; 
or

(f)     there shall be existing a default under this Lease as set forth in
Section 
20.

Tenant's request for consent shall include a copy of the proposed instrument
of 
assignment or sublease, if available, or else a statement of the proposed 
assignment or sublease in detail satisfactory to Landlord.  Landlord shall
have 
the option (but not the obligation), in lieu of granting its consent to a 
proposed assignment or sublease, to terminate the Lease, or that portion 
proposed to be assigned or subleased, effective upon the date of the proposed 
assignment or sublease by giving Tenant written notice of such termination.

Notwithstanding Landlord's consent to any assignment or sublease, the
liability 
of Tenant and of any guarantor of Tenant's obligations under this Lease shall 
remain primary and Landlord's acceptance of Basic Annual Rent, additional rent 
and other charges from persons other than Tenant shall not operate to
discharge 
or in any way diminish such liability.

In the event of any such assignment or subletting, Tenant shall deliver to the 
Landlord at the time of such assignment or subletting a written agreement from 
the assignee, or subtenant agreeing with Landlord to perform Tenant's 
obligations under the Lease.

If the Basic Annual Rent, additional rent and other charges payable to Tenant 
under such assignment or sublease exceed the Basic Annual Rent, the additional 
rent and other charges payable under this Lease, Tenant shall pay to Landlord, 
as additional rent, one half of the amount of the excess.  Landlord's
acceptance 
of a check in payment of any obligations of Tenant under this Lease from a 
person other than Tenant shall not be construed as an implied consent by 
Landlord to an assignment of this Lease or subletting under it.

Any assignment of this Lease made hereunder shall be upon the express
condition 
that the assignee and Tenant shall promptly execute, acknowledge and deliver
to 
Landlord an agreement in form and substance satisfactory to Landlord whereby
the 
assignee shall agree to be personally bound by the terms, covenants,

and conditions of this Lease on Tenant's part to be performed and whereby the 
assignee shall expressly agree that the provisions of this Section shall, 
notwithstanding such assignment or transfer, continue to be binding upon it
with 
respect to all future assignments and transfers.

Any sublease of the Premises, or any part thereof, shall be expressly subject
to 
the terms of this Lease and shall contain the agreement of the subtenant 
thereunder that, upon Landlord's written request, it will pay all rents under 
the sublease directly to Landlord.

The provisions of this Section shall also be applicable to any sublease or
assignment by any sublessee or assignee or other person(s) or entity deriving 
its interest through Tenant.

(b)     If this Lease shall be assigned, or if the Premises or any part
thereof be sublet or occupied by anybody other than Tenant and its employees, 
Landlord, after default by Tenant hereunder, may collect the rents from such 
assignee, subtenant or occupant, as the case may be, and apply the net amount 
collected to the Basic Annual Rent herein reserved, but no such assignment, 
subletting, occupancy or collection shall be deemed a waiver of the
requirements 
set forth in subparagraph (a) of this Section, the acceptance by Landlord of 
such assignee, subtenant or occupant, as the case may be, as a tenant, or a 
release of Tenant from the future performance by Tenant of its covenants, 
agreements and obligations contained in this Lease.  The consent by Landlord
to 
an assignment or subletting shall not in any way be construed to relieve
Tenant 
from obtaining the express consent in writing of Landlord to any further 
assignment or subletting.  No assignment, subletting or use of the Premises 
shall affect the purpose for which the Premises may be used as stated in
Section 
2.

(c)     The listing of any name other than that of Tenant, whether on the
doors of 
the Premises or on the Building directory, or otherwise, shall not operate to 
vest any right or interest in this Lease or in the Premises or be deemed to be 
the written consent of Landlord mentioned in this Section, it being expressly 
understood that any such listing is a privilege extended by Landlord revocable 
at will by written notice to Tenant.

(d)     Tenant further covenants and agrees that it will not sublease space
from 
or take an assignment of a lease covering space in the Building from any other 
Building tenant or sublease to or assign this Lease to any other Building 
tenant.

(e)     Any reasonable legal expenses incurred by Landlord by reason of any 
proposed assignment or subletting shall be paid by Tenant whether or not the 
transaction shall be consummated.

Notwithstanding anything contained herein to the contrary, so long as MFS 
Intelenet of Massachusetts, Inc. or any Related Entity (as hereafter defined)
is 
the Tenant in possession of the Premises, Tenant shall have right, without the 
consent or approval of Landlord, and without any recapture rights or right to 
excess rents of, or payments of any fees to, Landlord:

(i)     assign its interest in this Lease (a) to any corporation which is a 
successor to Tenant either by merger or consolidation, or (b) to a purchaser
of 
all or substantially all of Tenant's stock or assets, or (c) to a corporation
or 
other entity which shall directly or indirectly control, be under the control 
of, or be under common control with, MFS Intelenet of
Massachusetts, Inc. or MFS Communications Company, Inc. (any such entity being
a 
"Related Entity"), provided that any such assignee has a net worth greater
than 
the higher of the net worth of Tenant on (1) the date hereof or (2) the date
of 
such assignment, or

(ii)    sublease all or any portion of Premises to a Related Entity.

For purposes hereof, "control" shall be deemed to mean the direct or indirect 
ownership of more than fifty percent of the outstanding voting stock of a 
corporation or other majority equity and control interest if not a
corporation.  
Without limiting the foregoing, the collocation of telecommunications
equipment 
in the Premises not owned by Tenant shall not constitute a prohibited
assignment 
of sublease or require the consent of Landlord.

20.     Default:

(a)     If Tenant shall default in the payment of the Basic Annual Rent, 
additional rent, or any other charges or sums due hereunder and such default 
shall continue for ten (10) days (after notice from Landlord to Tenant; 
provided, however, that Landlord shall not be required to give such notice
more 
than one time in any Lease Year), or if Tenant shall default in the
performance 
of any other of its obligations and such default shall continue for thirty
(30) 
days after written notice thereof by Landlord to Tenant (except that if Tenant 
cannot reasonably cure any such default within said thirty (30) day period,
this 
period may be extended for a reasonable period of time not exceeding thirty
(30) 
additional days, provided that Tenant commences to cure such default within
the 
thirty (30) day period and proceeds diligently thereafter to effect such
cure), 
or if Tenant or the Guarantor (as such term is defined in Section 36 hereof) 
shall file a petition under any bankruptcy, insolvency law or code, or if such
a 
petition filed against Tenant or Guarantor is not dismissed within sixty (60) 
days, or if Tenant or Guarantor shall be adjudicated bankrupt or insolvent 
according to law, or if Tenant or Guarantor shall make any assignment for the 
benefit of creditors, or if Tenant or Guarantor shall file any petition
seeking 
a reorganization, arrangement or similar relief, or if a receiver, custodian, 
trustee or similar agent is appointed for all or a substantial portion of 
Tenant's or Guarantor's assets, or if Tenant's interest in this Lease is taken 
upon execution or other process of law in any action against Tenant or if the 
Guarantor shall attempt to rescind or terminate the Guaranty (as such term

is defined in Section 36 hereof), then Landlord may lawfully enter the
Premises 
and repossess the same as the former estate of Landlord, or terminate this
Lease 
by written notice to Tenant and. in either event, expel Tenant and those 
claiming through or under Tenant, and remove their effects, without being
deemed 
guilty of any manner of trespass and without prejudice to any other remedy
which 
Landlord may have for arrears of Basic Annual Rent and additional rent and
other 
charges and sums due hereunder or proceeding on account of breach of covenant, 
and upon entry or notice as aforesaid, this Lease shall terminate.

In addition, Tenant covenants, in case of any default by Tenant hereunder, to 
pay Landlord all costs of enforcing Landlord's rights under this Lease 
(including, without limitation, reasonable attorneys' fees and actual out-of-
pocket expenses), reletting expenses (including without limitation, the costs
to 
prepare the Premises for a new tenant) and brokerage fees, and in addition, 
liquidated damages of any one of the following elected by Landlord: (i) the 
amount by which, at the termination of the Lease, the then present value
(using 
as a discount factor the current interest rate on U.S. Treasury bills having a 
maturity equivalent to the unexpired Term of the Lease) of the aggregate of
the 
Basic Annual Rent (including, without limitation, the Real Estate Tax and 
Operating Cost payments -projected on the basis of experience under this
Lease) 
and other sums payable hereunder projected over a period from such termination 
until the normal expiration date of the Term, exceeds the then present value 
(using as a discount factor the current interest rate on U.S. Treasury bills 
having a maturity equivalent to the unexpired Term of the Lease) of the 
aggregate projected fair market rental value of the Premises for such period,
or 
(ii) an amount equal to the Basic Annual Rent, plus Operating Costs and Real 
Estate Tax payments projected on the basis of experience under this Lease not
so 
terminated (subject to off-set for net rents actually received from reletting 
after subtraction of the expenses of reletting), payable upon the due dates as 
specified herein.

(b)     Landlord may bring legal proceedings for the recovery of such damages,
or 
any installments thereof, from time to time at its election, and nothing 
contained herein shall be deemed to require Landlord to postpone suit until
the 
date when the Term of this Lease would have expired if it had not been 
terminated hereunder.

(c)     Nothing herein contained shall be construed as limiting or precluding
the 
recovery by Landlord from Tenant of any sums or damages (including, without 
limitation, reasonable attorney's fees and expenses) to which, in addition to 
the damages particularly provided above, Landlord may lawfully be entitled by 
reason of any default hereunder on the part of Tenant.  Landlord and Tenant 
agree that, for the purpose of computing liquidated damages, the Real Estate
Tax 
and Operating Cost payments for the period between the termination of this
Lease 
pursuant to this Section and the normal expiration date shall be computed by 
multiplying the Real Estate Tax and Operating Cost payment for the year 
immediately preceding the year in which termination occurs times the number of 
years and any fraction thereof

remaining of the full Term (as it may have been extended hereunder) hereby 
granted on the assumption that the amount of such Real Estate Tax and
Operating 
Cost payments for the immediately preceding year would have remained constant 
for each subsequent year during the entire Term of this Lease (as it may have 
been extended hereunder).  This same principle shall apply to the twelve (12) 
month period following termination if Landlord shall elect to recover under 
(iii) above.  If this Lease and the Term shall terminate pursuant to this 
Section prior to the determination of the initial Real Estate Tax and
Operating 
Cost payments, such payments shall be reasonably estimated by Landlord, at its 
sole discretion.  Landlord shall not be obligated to mitigate its damages, but 
shall market the Premises for lease with the broker then marketing space in
the 
Building.

(d)     Payments of Basic Annual Rent, additional rent, Real Estate Taxes, 
Operating Cost payments and any other obligations of Tenant which are not paid 
on the date due shall, at the option of Landlord, bear interest at the rate 
equal to the "Base Rate" from time to time established by The First National 
Bank of Boston, plus two (2) percent per annum from the due date.

21.     Landlord's Right to Cure: If Tenant shall default in the observance or 
performance of any term, covenant or condition on its part to be observed or 
performed under this Lease, Landlord, without being under any obligation to do 
so and without thereby waiving such default, may remedy such default for the 
account and at the expense of Tenant, immediately and without notice in case
of 
emergency, or in any other case, if Tenant shall fail to remedy such default 
with all reasonable diligence within the time set forth under Section 20 and 
after Landlord shall have notified Tenant of such default.  If Landlord makes 
any expenditures or incurs any obligations for the payment of money in 
connection therewith, including, but not limited to, reasonable attorney's
fees, 
such sums paid or obligations incurred, with interest at the rate of interest 
set forth in Section 20(d), shall be paid to Landlord by Tenant as additional 
rent hereunder.

22.     Subordination: This Lease is subject and subordinate in all respects
to 
all existing mortgages and ground leases and other matters of record and, 
provided Tenant is provided with a so-called non-disturbance agreement to all 
mortgages and ground leases which may hereafter be placed on or affect this 
Lease, the Property, or Landlord's interest or estate therein, and to each 
advance made or hereafter to be made under any such mortgages, and to all 
renewals, modifications, consolidations, replacements and extensions thereof
and 
all substitutions therefor.  This Section shall be self-operative and no
further 
instrument of subordination shall be required.  In confirmation of such 
subordination, Tenant shall execute and deliver promptly any certificate 
acknowledging or confirming such subordination that Landlord or any mortgagees 
or their respective successors in interest may request.  Notwithstanding the 
foregoing, any mortgagee may elect at any time to subordinate its mortgage to 
this Lease in whole or in part.  In the event of an assignment to any
mortgagee 
of this Lease or any payments due hereunder, such mortgagee shall have no 
liability for Landlord's obligations unless the

same shall have been expressly assumed in writing by such mortgagee or unless 
such mortgagee shall have obtained indefeasible title to the Property.  No act 
or failure to act on the part of Landlord which would entitle Tenant under the 
terms of this Lease, or by law, to be relieved of Tenant's obligations
hereunder 
or to terminate this Lease shall result in such release or termination unless 
Tenant shall have given written notice thereof to any mortgagee whose address 
has been furnished to Tenant, and such mortgagee, after receipt of such
notice, 
has failed to correct the condition complained of within a reasonable time 
thereafter, including such time as may be necessary in order to obtain 
possession of the Property.

Simultaneously with the execution of this Lease, Landlord shall provide Tenant 
with a so-called Non-Disturbance Agreement from the current holders of all 
existing mortgages or ground leases on or respecting the Property, which Non-
Disturbance Agreement shall be in the form currently used by the holders of
the 
first mortgage.

23.     Surrender of Possession: Holdover:

(a)     At the expiration or earlier termination of the Term of this Lease, as
it 
may have been extended hereunder, Tenant will remove Tenant's property, 
equipment and trade fixtures and shall peaceably yield up to Landlord the 
Premises in the same condition as they were on the Commencement Date, together 
with the Improvements made pursuant to Section 7 hereof (unless otherwise 
requested by Landlord pursuant to the provisions of this Lease), except for 
reasonable wear and tear and damage by fire or other casualty covered by 
Landlord's insurance or condemnation.

(b)     If Tenant remains in the Premises beyond the expiration or
earlier termination     of the Term of this Lease, as it may have been validly
extended hereunder,     such holding over shall not be deemed to create any
tenancy, but the Tenant shall be a Tenant-at-Sufferance only and shall pay
rent 
to Landlord at the times and manner determined by Landlord at a daily rate in
an 
amount equal to one and one half (1-1/2) times the daily rate of the Basic 
Annual Rent, additional rent and other sums payable under this Lease as of the 
last day of the Term of this Lease, as it may have been validly extended 
hereunder.

24.     Notices: All notices or other communications which are required or 
permitted herein shall be in writing and be given by sending by overnight 
prepaid air courier utilizing receipt or by registered or certified mail, 
postage prepaid, return receipt requested, addressed to the parties as
follows:

IF TO LANDLORD:              c/o WASA Management
30 Federal Street
Boston, Massachusetts 02110

with a copy to: Andrew M., Pearlstein, Esq.
Goldstein & Manello, P.C.
265 Franklin Street
Boston, Massachusetts 02110

IF TO TENANT:   MFS Intelenet of Massachusetts, Inc. 580 Winter Street
Waltham, Massachusetts

with a copy to: c/o MFS Telecom, Inc.
One Tower Lane, Suite 1600
Oakbrook Terrace, Illinois 60181 Attn: Real Estate & General Counsel

or at such other address as the party to whom notice is to be given may have 
furnished to the other party in writing in accordance herewith.  Any such 
communication shall be deemed to have been given on the business day after 
dispatch if sent by overnight air courier (unless the receipt shows otherwise) 
or on the fifth business day after posting if sent by mail.

25.     Rules and Regulations: Tenant will faithfully observe and comply with
such 
rules and regulations as Landlord may now have or hereafter at any time or
from 
time to time may make and may communicate in writing to Tenant, which in the 
judgment of Landlord shall be necessary for the reputation, safety, care or 
appearance of the Building, or the preservation of good order therein, or the 
operation or maintenance of the Building, or any equipment relating thereto,
or 
the comfort of tenants or others in the Building (the "Rules and
Regulations").  
Set forth on Exhibit C attached hereto are the Rules and Regulations in effect 
as of the date of execution of this Lease.  If this Lease shall conflict with 
any such Rules and Regulations, the provisions of this Lease shall control.  
Landlord shall not have any duty or obligation to enforce the Rules and 
Regulations or the terms, covenants or conditions in any other lease as
against 
any other tenant (but Landlord shall not enforce the Rules and Regulations in
a 
discriminatory manner) and Landlord shall not be liable to Tenant for
violation 
of the same by other tenants, their servants, employees, agents, visitors, 
invitees or licensees.

26.     Quiet Enjoyment: The Tenant, on paying Basic Annual Rent, additional
rent 
and other sums payable hereunder and performing the covenants of this Lease on 
its part to be performed, shall and may peaceably and quietly have, hold and 
enjoy the Premises for the Term of this Lease (as it may have been extended 
hereunder) free from hindrance or molestation by any person claiming by,
through 
or under Landlord.

27.     Limitation of Landlord's Liability: The term "Landlord", as used in
this 
Lease, so far as covenants or obligations to be performed by Landlord are 
concerned, shall be limited to mean and include only the owner or owners at
the 
time in question of the Property, and in the event of any transfer or
transfers 
of title to said Property, the Landlord herein named (and in case of any

subsequent transfers or conveyances, the then grantor) shall be automatically 
relieved from and after the date of such transfer or conveyance of all
liability 
as respects the performance of any covenants or obligations on the part of the 
Landlord contained in this Lease thereafter to be performed, it being intended 
hereby that the covenants and obligations contained in this Lease on the part
of 
Landlord shall, subject as aforesaid, be binding on the Landlord, its
successors 
and- assigns, only during and in respect of their respective successive
periods 
of ownership of the Property.  Tenant, its successors and assigns, agrees it 
shall not assert nor seek to enforce any claim for breach of this Lease
against 
any of Landlord's assets other than Landlord's interest in the Property and in 
the rents, issues and profits thereof, and Tenant agrees to look solely to
such 
interest for the satisfaction of any liability of or claim against Landlord 
under this Lease, it being specifically agreed that in no event whatsoever
shall 
Landlord (which term shall include, without limitation, any beneficiary of any 
trust of which Landlord is a trustee or any general or limited partners of 
Landlord if Landlord is a general or limited partnership), ever be personally 
liable for any such liability.  In no event shall Landlord be liable for any 
indirect or consequential damages, including without limitation, loss of 
profits, loss of business, damage to reputation or loss of rental under any 
sublease or assignment arrangement.  Nothing contained herein shall prohibit
any 
action by Tenant against Landlord for, specific performance.

28.     Binding Agreement: This Lease shall bind and inure to the benefit of
the 
parties hereto and such respective heirs, representatives, successors or
assigns 
as are permitted by this Lease.  This Lease contains the entire agreement of
the 
parties and may not be modified except by an instrument in writing.

29. Notice of Lease: Tenant agrees that it will not record this Lease.
Landlord and Tenant shall, upon request of either, execute and deliver a
notice 
of this
Lease in such recordable form as may be permitted by applicable statute.

30.     Brokerage: Landlord and Tenant each represents and warrants to the
other 
that it has dealt with no broker except The Niles Company and CB Commercial
Real 
Estate Group, Inc. in connection with this transaction.  Landlord hereby
agrees 
to pay all compensation which may be due by it to The Niles Company and CB 
Commercial Real Estate Group, Inc. as set forth in a separate agreement. 
Tenant 
agrees to hold harmless and indemnify Landlord from and against any and all 
costs, (including without limitation reasonable attorneys' fees), expenses, or 
liability for any compensation, commissions and/or charges claimed by any
other 
broker or agent claiming to have dealt with Tenant in connection with this
Lease 
or the negotiation thereof.

31.     Claims in Bankruptcy: Nothing herein shall limit or prejudice the
right of 
Landlord to prove and obtain in a proceeding for bankruptcy, insolvency, 
arrangement or reorganization, by reason of the termination, an amount equal
to 
the maximum allowed by a statute of law in effect at the time when, and 
governing the proceedings in which, the damages are to be proved, whether or
not 
the amount is greater to, equal to, or less than the amount of the loss or 
damage which Landlord has suffered.

32.     Estoppel Certificates: At Landlord's request, from time to time,
Tenant 
agrees to execute and deliver to Landlord within ten (10) days after requested 
to do so by Landlord, a certificate which acknowledges tenancy and possession
of 
the Premises and recites such other facts concerning any provision of the
Lease 
or payments made under the Lease including, without limitation, the date to 
which rents have been paid, the amount of any security deposit, and whether 
Landlord is then in default in the performance of any obligation of Landlord 
under the Lease which a mortgagee or lender or a purchaser or prospective 
purchaser of the Building or any interest therein or any other party may 
reasonably request.


33.     General Provisions:

(a)     The various rights and remedies contained in this Lease and reserved
to 
each of the parties shall not be exclusive of any other right or remedy of
such 
party, but shall be construed as cumulative and shall be in addition to every 
other remedy now or hereafter existing at law, in equity, or by statute.  No 
delay or omission of the right to exercise any power by either party shall 
impair any such right or power, or shall be construed as a waiver of any
default 
or as acquiescence in any default.  No covenant, term or condition shall be 
deemed waived by Landlord except by a writing.  One or more waivers of any 
covenant, term or condition of this Lease by either party shall not be
construed 
by the other party as a waiver of a subsequent breach of the same covenants, 
terms or conditions or any other covenant, term or condition.  The consent or 
approval of either party to or any act by the other party of a nature
requiring 
consent or approval shall not be deemed to waive or render unnecessary consent 
to or approval of any subsequent similar act.

No payment by Tenant, or acceptance by Landlord, of a lesser amount than shall 
be due from Tenant to Landlord shall be treated otherwise than as a payment on 
account.  The acceptance by Landlord of a check for a lesser amount with an 
endorsement or statement thereon, or upon any letter accompanying such check, 
that such lesser amount is payment in full, shall be given no effect, and 
Landlord may accept such check without prejudice to any other rights or
remedies 
which Landlord may have against Tenant.

(b)     Payments to Landlord under this Lease are rental for the use of the 
Premises, and nothing herein contained shall be deemed or construed to make 
Landlord a partner or associate of Tenant in the conduct of any business, nor
as 
rendering Landlord liable for any debts, liabilities or obligations incurred
by 
Tenant in the conduct of any business, it being expressly agreed that the 
relationship between the parties is, and shall at all times remain, that of 
landlord and tenant.

(c)     All amounts payable by Tenant to Landlord under any provision of this 
Lease other than Basic Annual Rent shall be deemed to be additional rental for 
the use of the Premises, and Landlord shall have the same remedies for the 
nonpayment of such amounts as for the nonpayment of Basic Annual Rent.

(d)     Where the words "Landlord" and "Tenant" are used in this Lease, they
shall 
include Landlord and Tenant and shall apply to persons, both men and women, 
associations. partnerships and corporations, and in reading this Lease, the 
necessary grammatical changes required to make the provisions hereof mean and 
apply to them shall be made in the same manner as if written into the Lease.

(e)     Tenant hereby declares that in entering into this Lease, Tenant relied 
solely upon the statements contained in this Lease and fully understanding
that 
no agents or representatives of Landlord have authority to in any manner
change, 
add to or detract from the terms of this Lease.  Landlord shall not be deemed
to 
have made any other representations or agreements, express or implied.

(f)     The invalidity of one or more of the provisions of this Lease shall
not 
affect the remaining portions of this Lease; and, if any one or more of the 
provisions of this Lease should be declared invalid by final order, decree or 
judgment of a court of competent jurisdiction, this Lease shall be construed
as 
if such invalid provisions had not bee included in this Lease.

(g)     If Tenant shall be two or more persons or entities, each such person
shall 
be jointly and severally liable for the payment of all sums due to Landlord
from 
Tenant under this Lease and the performance of all of Tenant's covenants, 
agreements, or obligations under this Lease.

(h)     If either Landlord or Tenant shall be delayed or prevented from the 
performance of any act required hereunder by reason of acts of God, strikes, 
lockouts, labor troubles, inability to procure materials, restrictive 
governmental laws or regulations or other cause without fault beyond their 
control (financial inability and Tenant's obligation to pay Rent excepted), 
performance of such acts shall be excused for the period of such delay and the 
period for the performance of any act shall be extended for a period
equivalent 
to the period of such delay.

(i)     Where the word "Term" is used in this Lease, it shall also include the 
word "Extended Term" as the context shall so require.

(j)     Whenever the approval or consent of Landlord is required hereunder,
such 
approval or consent may be withheld or conditioned in Landlord's sole
discretion 
unless expressly otherwise set forth.

34.     Landlord's Reservation of Rights to Change the Property: Landlord
hereby 
expressly reserves the right, at any time and from time to time, but not any 
obligation, to alter, or otherwise modify (or eliminate) the locations, 
features, configuration and/or dimensions of all buildings, improvements, 
parking areas, approaches, roadways, service drives, entries, exits, curb
cuts, 
fire lanes, sidewalks, alleys, isles, islands, planted and landscaped areas, 
public restrooms, if any, and other facilities, areas or improvements
contained 
from time to time as a part of the Property, to raise buildings, or construct 
additional buildings and improvements on the Property, including, without 
limitation, one or more additional floors on the Building, to change the size, 
location or arrangement of the common areas, to place and remove in the 
corridors and other common areas, landscaping, decorative items

and structures for retail sales, promotional activities, or for any other 
reasonable purpose; provided that the exercise of Landlord's rights hereunder 
shall not materially and adversely affect the Premises or Tenant's use thereof 
for the Permitted Use.

35.     Environmental Matters: Tenant shall, at all times, comply with all 
applicable federal, state, and local environmental and other laws, ordinances, 
orders or regulations now or hereafter affecting or applicable to the Premises 
or the operation of Tenant's business at the Premises or the Property
including, 
without limitation, with respect to the operation and testing of Tenant's 
emergency generator and associated fuel tank (the foregoing laws, ordinances, 
orders, and regulations are hereinafter collectively referred to as 
"Environmental Laws").  Notwithstanding anything in this Lease to the
contrary, 
and without limiting the generality of the foregoing, Tenant shall not,
without 
Landlord's prior written consent, and subject to such conditions as may be 
imposed by Landlord and in strict compliance with all Environmental Laws, use, 
store, manufacture or otherwise generate, process, dispose of, or deposit in,
on 
or under the Property or into any septic, sewer, drainage or other system 
servicing the Property or suffer or permit the use, storage, manufacture or 
other generating, processing, disposal of or depositing in, on or under the 
Property or any septic, sewer, drainage or other system servicing the Property 
(collectively, "Dealing With or Dealt With"), any oil, grease, chemical, 
hazardous or dangerous substance regulated by any public authority
(hereinafter 
referred to as "Hazardous Substances") at, in, upon or under the interior or 
exterior of the Premises, or the Property, whether or not above or below
ground, 
or in any pipes, mains, conduits or ducts thereof or thereat.  In connection 
with any Tenant request for Landlord consent hereunder, Tenant shall provide 
Landlord with such data, specifications and professional opinions as Landlord 
may reasonably request.

Tenant does hereby agree to indemnify, defend, and save and hold harmless 
Landlord from all claims, actions, hens, demands, costs, expenses, fines and 
judgments resulting from or arising by reason of the following: (i) any spills 
or contamination of air, soil or water or otherwise by Hazardous Substances at 
or around the Premises or the Property or upon removal therefrom caused by 
Tenant, its agents, servants, employees, contractors or invitees; (ii) the 
violation of any Environmental Laws by Tenant or its agents, servants, 
employees, contractors or invitees; and (iii) the violation of any of the 
provisions of this Section of this Lease by Tenant or its agents, servants, 
employees, contractors or invitees, in any case, including, without implied 
limitation, reasonable engineering, attorney's and other professional fees and 
expenses for evaluating, and/or curing the same and for consulting,
engineering, 
defending against any such claims or removing such .Hazardous Substances, and 
for enforcing this indemnification.

Upon ten (10) days prior written request from Landlord, Tenant shall execute, 
acknowledge and deliver to Landlord or to landlord's mortgagee(s), or to such 
other persons or parties as Landlord shall from time to time designate, a 
written statement in form and specifics satisfactory to Landlord certifying
that 
Tenant has not been (or to what extent Tenant has been) Dealing With or Dealt 
With any Hazardous Substances on or about the Premises or the Property and
that 
any Hazardous Substances used, processed or generated at the Premises or by it 
at the Property

have been used or removed and disposed of properly, and of Tenant's strict 
compliance with this Section.

36.     Guaranty: all be guaranteed The obligations of the Tenant hereunder
shall 
be guaranteed by MFS Communications Company, Inc. (the "Guarantor") pursuant
to 
a Guaranty to be executed by Guarantor simultaneously with the execution of
this 
Lease substantially in the form of Exhibit "D" attached hereto (the
"Guaranty").

37.     Right of First Offer: So long as this Lease is in full force and
effect 
and Tenant is not in default under Article 20 beyond the applicable grace 
periods set forth in Section 20(a), Tenant shall have a right of first offer, 
pursuant and subject to the following terms and conditions, to lease any 
rentable area contiguous to the Premises on the first floor of the Building 
except for the space shown on Exhibit A and marked "Exempt Space".  In the
event 
that, at any time during the Term, any such area becomes or is to become
vacant, 
and Landlord desires to lease said area other than to its then current
occupant 
(if any), Landlord shall first made a written offer to lease said area to 
Tenant, stating the rent that Landlord will accept and all other material
terms 
and conditions of the proposed lease (which rent and other terms and
conditions 
shall be consistent with other offerings then being made by Landlord for 
comparable space in the Building), and Tenant shall have a right of first
offer 
(subject to any similar right or option which may heretofore have been given
to 
another tenant) to lease said area by giving notice to Landlord to such effect 
within ten (10) days after notice of such offer from Landlord.  If such notice 
is not so given by Tenant, then Landlord shall be free to lease said area to 
anyone and Tenant shall have no further recourse with respect thereto except
in 
the event that, subsequent to the leasing of said area to a third party, said 
area again becomes available for rental as hereinabove set forth.  In any case 
in which Tenant shall have waived said right of first offer or said right
shall 
have expired, Tenant shall, upon request of Landlord, execute and deliver in 
recordable form an instrument indicating such waiver or expiration, which 
instrument shall be conclusive in favor of all persons relying thereon in good 
faith.

IN WITNESS WHEREOF, the parties hereto have executed this Lease in multiple 
counterparts, the original as a sealed instrument on the day and year first 
above written.

LANDLORD:

580 Winter Street Corp.

By:             /s/

TENANT:
MFS Intelenet of
Massachusetts, Inc.

BY:             /s/
its             hereunto
duly authorized



EXHIBIT "C"

Rules and Regulations

1.      The sidewalks, entrances, passages, courts, elevators, vestibules, 
stairways, corridors or halls of the Building shall not be obstructed or 
encumbered or used for any purpose other than ingress and egress to and from
the 
premises demised to any tenant or occupant.

2.      No awnings or other projections shall be attached to the outside walls
or 
windows of the Building without the prior consent of Landlord.  No curtains, 
blinds, shades, or screens shall be attached or hung in, or used in connection 
with, any window or door of the premises demised to any tenant or occupant, 
projections, curtains, blinds, shades, screens, or other fixtures permitted by 
Landlord must be of a quality type, design and color, and attached in a
manner, 
approved by Landlord.

3.      No sign, advertisement, object notice or other lettering shall be 
exhibited, inscribed, painted or affixed on any part of the outside or inside
of 
the premises demised to any tenant or occupant of the Building without the
prior 
consent of Landlord.  Interior signs on doors and directory tables, if any, 
shall be of a size, color and style approved by Landlord.

4.      The sashes, sash doors, skylights, windows and doors that reflect or
admit 
light and air into the halls, passageways or other public places in the
Building 
shall not be covered or obstructed, nor shall any bottles, parcels, or other 
articles be placed on any window sills.

5.      No show cases or other articles shall be put in front of or affixed to
any 
part of the exterior of the Building, nor placed in the halls, corridors, 
vestibules or other parts of the Building without Landlord's prior consent.

6.      The water and wash closets and other plumbing fixtures shall not be
used 
for any purposes other than those for which they were constructed, and no 
sweepings, rubbish, rags, or other substances shall be thrown therein.

7.      No tenant or occupant shall mark, paint, drill into, or in any way
deface 
any part of the Building or the premises demised to such tenant or occupant. 
No 
boring, cutting or stringing of wires shall be permitted, except with the
prior 
consent of the Landlord, and as Landlord may direct.  No tenant or occupant 
shall install any
resilient       tile or similar floor covering in the premises demised to such 
tenant or
occupant        except in a manner approved by Landlord.

8.      No bicycles, vehicles or animals of any kind shall be brought into or
kept 
in or about the premises demised to any tenant.  No cooking shall be done or 
permitted in the Building by any tenant without the approval of Landlord.  No 
tenant shall cause or permit any unusual or objectionable odors to emanate
from 
the premises demised to such tenant.

9.      No tenant shall make, or permit to be made, any unseemly or disturbing 
noises or disturb or interfere with other tenants or occupants of the Building 
whether by the use of any musical instrument, radio, television set or other 
audio device, unmusical noise, whistling, singing, or in any other way. 
Nothing 
shall be thrown out of any doors or windows.

10.     Each tenant must, upon the termination of its tenancy, restore to
Landlord 
all keys of stores, offices and toilet rooms, either furnished to, or
otherwise 
procured by, such tenant.  Locks to premises shall not be changed or added 
without permission of the Landlord.

11.     Each tenant shall, at its expense, provide artificial light in the 
premises demised to such tenant for Landlord's agents, contractors, and 
employees while making repairs or alterations in said premises.

12.     No premises shall be used, or permitted to be used, for lodging or 
sleeping, or for any immoral or illegal purpose.

13.     There shall not be used in the Building, either by any tenant or
occupant 
or by their agents or contractors, in the delivery or receipt of merchandise, 
freight or other matter, any hand trucks or other means of conveyance except 
those equipped with rubber tires rubber side guards and such other safeguards
as 
Landlord may require.

14.     Canvassing, soliciting and peddling in the Building are prohibited and 
each tenant and occupant shall cooperate in seeking their prevention.

15.     If the premises demised to any tenant becomes infested with vermin,
rodents, insects, or pests, such tenant, at its sole cost and expense, shall 
cause its premises to be exterminated from time to time, to the satisfaction
of 
Landlord, and shall employ such exterminators therefore as shall be approved
by 
Landlord.

16.     All damages done to the Building by the installation or removal of any 
property of a tenant, or done by a tenant's property while in the Building, 
shall be repaired at the expense of such tenant.

17.     Each tenant shall keep its premises neat and clean.  Landlord shall be
in 
no way responsible to the tenants, their agents, employees or invitees for any 
loss of property from their premises or public areas or for any damages to any 
property thereon from any cause whatsoever unless caused by Landlord's gross 
negligence or willful act or omission.

18.     Nothing shall be swept or thrown into the corridors, halls, elevator 
shafts or stairways.  No birds or animals shall be brought into or kept in, on 
or about the Building.

19.     No machinery of any kind other than standard office equipment shall be 
operated by a tenant on its leased premises without the prior written consent
of 
Landlord which consent shall not be unreasonably withheld or delayed.

20.     Tenants shall not do anything, or permit anything to be done, in or on 
about the Building, or bring or keep anything therein, including without 
limitation any inflammable or explosive fluid or substance, that will in any
way 
increase the possibility of fire or other casualty, or do anything in conflict 
with valid laws, rules or regulations of any governmental authority unless 
permitted by Landlord.

21.     Landlord reserves the right to rescind any of these rules and
regulations 
and to make such other and further rules and regulations as in its judgment 
shall from time to time be needful for the safety, protection, care and 
cleanliness of the Building, the operation thereof, the preservation of good 
order therein and the protection and comfort of the tenants and their agents, 
employees and invitees, which rules and regulations, when made and written 
notice thereof is given to a tenant, shall be binding upon it in like manner
as 
if originally herein prescribed so long as the same are reasonable and
uniformly 
enforced.

  
 

Exhibit "D"

GUARANTY

For valuable consideration, the undersigned, MFS Communications Company, Inc.,
a 
Delaware corporation, of 200 Kiewit Place, 3555 Farnam Street, Omaha, Nebraska 
68131, (hereinafter referred to as the "Guarantor"), for its legal 
representatives, successors and assigns, in order to induce 580 Winter Street 
Corp., with offices at c/o WASA Management, 30 Federal Street, Boston, 
Massachusetts ("Landlord") to enter into a lease of even date (the "Lease") 
between Landlord and MFS Intelenet of Massachusetts, Inc. (the "Tenant"), for 
certain premises at 580 Winter Street, Waltham, Massachusetts described in
said 
Lease (the "Premises"), hereby unconditionally guarantees to the Landlord and 
its successors or assigns, the full and prompt payment and performance of all 
liabilities and obligations of the Tenant to the Landlord under the Lease of 
every kind, nature and description including, without limitation, the payment
of 
rent and other charges due under the Lease, whether recovery upon such 
obligations may be or hereafter become barred by any statute of limitations,
or 
whether such lease obligations may be or hereafter become otherwise 
unenforceable (the "Lease Obligations").  This Guaranty will apply to the
Lease, 
any extension or renewal of the Lease, and any holdover period following the 
term of the Lease, or any such extension or renewal.

Any act of Landlord, or the successors or assigns of Landlord, consisting of a 
waiver of any of the terms or conditions of the Lease, or the giving of any 
consent to any matter related to or thing relating to the Lease, or the
granting 
of any indulgences or extensions of time to Tenant, may be done without notice 
to Guarantor and without affecting the obligations of Guarantor under this 
Guaranty.

The obligations of Guarantor under this Guaranty will not be affected by 
Landlord's receipt, application, or release of security given for the 
performance of Tenant's obligations under the Lease, nor by any modification
of 
the Lease, including, without limitation, the alteration, enlargement, or
change 
of the Premises, except that in case of any such modification, the liability
of 
the Guarantor will be deemed modified in accordance with the terms of any such 
modification.

The obligation of the Guarantor is primary and not secondary.  The Guarantor 
hereby waives any right to require the Landlord to (a) proceed against or 
exhaust any security held from the Tenant or remedy against Tenant prior to 
proceeding under this Guaranty; (b) proceed against any other guarantor of the 
Lease Obligations guaranteed hereby or (c) pursue any other remedy in
Landlord's 
power whatsoever.

The liability of Guarantor under this Guaranty will not be affected by (a) the 
release or discharge of Tenant from its obligations under the Lease in any 
creditors', receivership, bankruptcy, or other proceedings, or the
commencement 
or pendency of any such proceedings; (b) the impairment, limitation, or 
modification of the liability of Tenant or the estate of Tenant in
bankruptcy-, 
or of any remedy for the enforcement of Tenant's liability under the Lease, 
resulting from the operation of any present or

future bankruptcy code or other statute, or from the decision in any court;
(c) 
the rejection or disaffirmation of the Lease in any such proceedings; (d) the 
assignment or transfer of the Lease or sublease of all or part of the Premises 
by Tenant; (e) any disability or other defense of Tenant under the Lease.

Guarantor:      (a) waives any right of subrogation against Tenant by reason
of any 
payments or acts of performance by Guarantor in compliance with the
obligations 
of Guarantor under this Guaranty; (b) waives any other right that Guarantor
may 
have against Tenant by reason of any one or more payments or acts in
compliance 
with the obligations of Guarantor under this Guaranty; (c) subordinates any 
liability or indebtedness of Tenant held by Guarantor to the obligations of 
Tenant to Landlord under the Lease; and (d) waives all suretyship defenses and 
defenses of like nature.

The Guarantor hereby waives all presentments, demands for performance notices
of 
non-performance, protests, notices of dishonor, and notices of acceptances of 
this Guaranty.  The Guarantor hereby waives any right or claim of right to
cause 
a marshaling of the Tenant's assets.  No delay on the pat of the Landlord in
the 
exercise of any right, power or privilege under the Lease with the Tenant or 
under this Guaranty shall operate as a waiver of any such privilege, power or 
right.

The Guarantor agrees to pay on demand reasonable attorneys, fees and expenses 
incurred by the Landlord in the enforcement of this Guaranty, whether or not 
suit is commenced.

This Guaranty shall continue in full force and effect until the complete
payment 
and performance of the Lease Obligations; provided, however, that 
notwithstanding the forgoing, this Guaranty shall be released on the date
which 
is the fifth (5th) anniversary of the Rent Commencement Date provided that (i) 
Tenant has not previously defaulted beyond the applicable grace period during 
the Term of the Lease; (ii) there is no default existing under Section 20 of
the 
Lease as of such date and no event has occurred which, with the passage of
time, 
could ripen into default; and (iii) Tenant has a net worth as of such date of 
not less than One Million ($1,000,000) Dollars determined in accordance with 
generally accepted accounting principles.  This Guaranty may not be changed, 
modified, discharged, or terminated orally or in any manner other than
agreement 
in writing signed by Guarantor and Landlord.

The Guarantor acknowledges that the Landlord has been induced by this Guaranty 
(among other things) to enter into the Lease with the Tenant heretofore 
described, and this Guaranty shall, without further reference of assignment, 
pass to, and may be relied upon and enforced by, any successor or assignee of 
the Landlord.

The Guarantor hereby consents to the jurisdiction of the courts of the 
Commonwealth of Massachusetts and the United States District Court for the 
District of Massachusetts, as well as to the jurisdiction of all courts to
which 
an appeal may be taken from such courts, for the purpose of any suit, action
or 
other proceeding arising out of or in connection with this Guaranty.  The 
Guarantor hereby

expressly waives any and all objections it may have as to the venue in any
such 
courts.

This Guaranty shall, for all purposes, be governed by and construed in 
accordance with the laws of the Commonwealth of Massachusetts to the maximum 
extent that the parties hereto may so lawfully agree, irrespective of the
place 
of execution.
EXECUTED as a sealed instrument this    day of October, 1994.
Witness
This is the third and final page of a Guaranty, dated October, 1994, from MFS 
Communications Company, Inc. to 580 Winter Street Corp.