LEASE AGREEMENT

PREMISES

1

CONSTRUCTION OF THE LANDLORD IMPROVEMENTS AND THE TENANT IMPROVEMENTS

1

INITIAL TERM

6

BASE RENT AND ADDITIONAL RENT

7

RENEWAL OF THE TERM

9

USE

11

ALTERATIONS

11

MAINTENANCE OF PREMISES

12

UTILITIES

15

SATELLITE DISH

15

SIGNS AND FLAGPOLES

16

EXPANSION OPTION

16

LANDLORD’S RIGHT OF ACCESS

20

TENANT’S INDEMNITY

20

LANDLORD’S INDEMNITY

20

INSURANCE

21

WAIVER OF SUBROGATION

22

CASUALTY

23

CONDEMNATION

24

COMPLIANCE WITH ENVIRONMENTAL LAWS

24

COMPLIANCE WITH PUBLIC ACCOMMODATION LAWS

26

LANDLORD’S WARRANTIES

27

TENANT’S DEFAULT

28

LANDLORD’S REMEDIES

29

LANDLORD’S DEFAULT AND TENANT’S REMEDIES

29

LATE CHARGES; INTEREST ON LATE PAYMENTS

30

QUIET ENJOYMENT

30

SUBORDINATION, ATTORNMENT & NON-DISTURBANCE

31

LANDLORD’S SALE OF PREMISES

31

BROKER’S COMMISSIONS

31

ESTOPPEL CERTIFICATE

31

HOLDING OVER

31

ASSIGNMENT AND SUBLETTING

32

RIGHT OF FIRST OFFER

32

MISCELLANEOUS

32

TIME OF ESSENCE

35

VALIDITY OF AGREEMENT

35

GUARANTY

35

INCENTIVES

37

ARBITRATION

37

Outline Specifications

The Land

Final Tenant Improvements Plans and Specifications

Tenant Allowances

Form of Tenant Acknowledgment Letter

Knowledge Individuals

Form of Subordination Non-Disturbance and Attornment Agreement

Form of Estoppel Certificate

Form of Guaranty

Approved General Contractors and Major Subcontractors

Title Exceptions

A.

Landlord desires to design, construct, and lease to Tenant a shell building (the Building ) and other improvements (the Building and other improvements specified in the Outline Specifications attached hereto as Exhibit A are sometimes referred to collectively as the Landlord Improvements ) on the real property owned by Landlord and described on Exhibit B (the Land ), in accordance with the terms and subject to the conditions of this Lease.

B.

Tenant desires to have constructed and to lease from Landlord the Landlord Improvements in accordance with the terms and subject to the conditions of this Lease.

C.

Tenant desires to construct for its use additional interior improvements in the Building in accordance with the terms and subject to the conditions of this Lease.

(a)

Landlord shall furnish, at Landlord’s sole cost and expense, all of the materials, labor, and equipment necessary for the design and construction of the Landlord Improvements in accordance with the Outline Specifications. Landlord shall construct the Landlord Improvements in a good and workmanlike manner, and in accordance with all applicable statutes and building codes, governmental rules, regulations, and orders, and restrictive covenants applicable to the Premises ( Legal Requirements ).

(b)

Tenant shall retain space planners, architects, and engineers reasonably approved by Landlord to design all interior improvements (including, without limitation, space planning, preparation of the Final Tenant Improvements Plans and Specifications in the manner set forth below, special lighting, interior demising walls, floor and wall coverings, furniture systems, security systems, telephone and data cabling, excess HVAC for computer rooms, equipment, etc.)

(a)

Subject to Section 3(c), the term of this Lease (the Initial Term ) is the period that commences on the latter of (i) May 14, 2006, or (ii) six months after the date of Substantial Completion and tender of possession of the Landlord Improvements to Tenant (the Commencement Date ) and that expires at 11:59 p.m. (Dallas, Texas local time) on either the day prior to the 12th anniversary of the Commencement Date, if the Commencement Date occurs on the first day of a calendar month, or on the day prior to the 12th anniversary of the first day of the first full calendar month following the calendar month in which the Commencement Date occurs, if the Commencement Date does not occur on the first day of a calendar month, whichever is applicable (the Expiration Date ). The term Lease Year means each 12 calendar month period beginning on the Commencement Date. The first Lease Year includes any partial calendar month if the Commencement Date is not the first day of a calendar month.

(b)

Tenant has the right to renew the term of this Lease, as set forth in Section 5 below, and the Initial Term and any Renewal Term with respect to which Tenant exercises that option in accordance with Section 5 are collectively called the Term in this Lease.

(c)

If the date of Substantial Completion and tender of possession of the Landlord Improvements to Tenant does not occur by December 6, 2005, solely by reason of Tenant Delays or by reason of casualty damage covered by Section 18, then the Commencement Date will remain June 5, 2006, and Tenant shall commence paying Base Rent on June 5, 2006.

(d)

Within 15 days after Substantial Completion occurs, the parties will execute an Acknowledgment Letter in substantially in the form of Exhibit E .

(a)

Assuming the Building Square Footage is at least 75,000 rentable square feet and subject to adjustment as provided in Sections 4(b) and 39 and in Exhibit D , Tenant shall pay to Landlord base annual rent ( Base Rent ) for the Premises beginning on the Commencement Date as follows:

Lease Years

Annual Base Rent

Monthly Base Rent

$

992,250

$

82,687.50

$

1,053,000

$

87,750.00

$

1,117,500

$

93,125.00

(b)

If the certificate of Landlord’s architect provided under Section 2(q) shows that the Building Square Footage is less than 75,000 rentable square feet, then the Annual Base Rent and Monthly Base Rent numbers specified above, will be decreased by multiplying them by a number whose numerator is the Building Square Footage and whose denominator is 75,000. The full amount of the Tenant Allowances shall be paid to Tenant and will not be reduced even if the Building Square Footage is determined to be less than 75,000 rentable square feet. Any adjustment of the Base Rent under this Section 4(b) will be specified in the Acknowledgement Letter.

(c)

If the Commencement Date occurs on a day other than the first day of a calendar month, then the Base Rent for the month in which the Commencement Date occurs will be equal to the monthly installment amount specified above multiplied by a fraction, the numerator of which is the number of days in the period starting on the Commencement Date and ending on the last day of that month, and the denominator of which is the total number of days in that month.

(d)

If a termination of this Lease occurs prior to the Expiration Date for reasons other than Tenant’s default and if the effective date of termination is other than the last day of a calendar month, the parties will prorate the Base Rent payable with respect to the calendar month in which the effective date of termination occurs based on the number of days in that month, and Landlord shall promptly refund to Tenant, without demand, setoff or deduction, any previously paid Base Rent attributable to any period of time following the termination date.

(e)

Subject to Section 3(c), if the date of Substantial Completion and the tender of possession of the Landlord Improvements does not occur by the following dates (each of which is subject to extension by one day for each day of Excused Delay [except that the April 4, 2006 date set forth in Section 4(e)(iii) shall not be extended beyond October 5, 2006 unless the additional delay is caused by Tenant Delay]):

(A)

terminate this Lease effective as of the date Tenant gives such notice;

(B)

elect to take over completion of the Landlord Improvements, in which event Tenant shall be entitled to a credit against Base Rent for all reasonable costs incurred by Tenant in completing the Landlord Improvements; or

(C)

require Landlord to complete the Landlord Improvements and continue to allow free Base Rent and expense payment (or reimbursement) to accrue as provided in Section 4(e)(ii).

(a)

Except as otherwise provided in Section 12, Tenant may renew the Term for two successive renewal terms ( Renewal Terms ) of 60 months each so long as this Lease is in full force and effect and Tenant is not in default beyond all applicable grace, notice and cure periods in respect of the performance of any obligation it undertakes under the terms of this Lease both at the time that Tenant exercises each renewal option and at the time the Renewal Terms commence. Tenant will exercise each renewal option, if at all, by delivering written notice (the Option Notice ) to Landlord not less than two hundred seventy (270) days prior to the Expiration Date. The provisions of this Lease will govern the relationship between the parties during each Renewal Term, except that the Base Rent for each Renewal Term will be determined as provided below.

(b)

The annual Base Rent payable during each Renewal Term will be equal to 95% of the product of the Fair Market Rent (as defined below and as determined in accordance with the procedures described in this Section 5(b)) as of the date Tenant exercises its option to renew the Term for the ensuing Renewal Term times the Building Square Footage (or, if Tenant has exercised its Expansion Option under Section 12, times the sum of the Building Square Footage plus the number of rentable square feet in the Expansion). Initially Landlord will determine the Fair Market Rent by using its good faith judgment. Landlord will use its best efforts to provide written notice of its determination in that regard within 15 days after the date Tenant sends the Option Notice, but in no event later than 30 days after that date. Tenant will have a period (the Tenant Review Period ) of 30 days following the date of its receipt of Landlord’s notice of the rent it proposes as the Fair Market Rent within which to accept Landlord’s proposal or

to provide Landlord Tenant’s objections to Landlord’s proposal. If Tenant objects to Landlord’s initial proposal or fails to affirmatively accept that proposal in writing, the parties will use their best efforts to reach agreement with respect to the Fair Market Rent, but, if the parties fail to agree within 15 days after the expiration of the Tenant Review Period, determination of the Fair Market Rent will be made in accordance with the terms of Subsections 5(b)(i) through 5(b)(v) below. If Landlord fails to provide Tenant written notice of its initial proposal with respect to the Fair Market Rent within the 30-day period set forth above, Tenant may commence negotiations by providing the initial notice, in which event Landlord will have a period (the Landlord Review Period ) of 30 days following the date of its receipt of Tenant’s notice of the rent it proposes as the Fair Market Rent within which to accept Tenant’s proposal or to provide Tenant Landlord’s objections to Tenant’s proposal. If Landlord objects to Tenant’s initial proposal or fails to affirmatively accept that proposal in writing, the parties will use their best efforts to reach agreement with respect to the Fair Market Rent, but, if the parties fail to agree within 15 days after the expiration of the Landlord Review Period, determination of the Fair Market Rent will be made in accordance with the terms of Subsections 5(b)(i) through 5(b)(v) below. If determination of the Fair Market Rent in accordance with the following procedures becomes necessary, each party will place in a separate sealed envelope its final proposal as to the Fair Market Rent that will apply during the ensuing Renewal Term.

(c)

Fair Market Rent means the annual rental rate per square foot that comparable buildings located in the same market area as the Building and that are comparable in size, design, and quality to the Building would accept in comparable transactions involving a tenant whose creditworthiness is comparable to that of Tenant and whose other obligations under the lease would be comparable to those undertaken by Tenant in this Lease. In any evaluation of comparable transactions, the arbitrator will consider the annual rental rates per square foot, the use to which the tenant puts the leased premises, the extent of the tenant’s liability for the performance of the covenants set forth in the lease, abatement provisions reflecting free rent or no rent during the period of construction or subsequent to the commencement date as to the building in question, brokerage commissions, if any, that would be payable by the landlord, length of the lease term, size and location of premises being leased, building standard work letter or tenant improvement allowances, if any, and other generally applicable conditions of tenancy for those comparable transactions. The intent is that Tenant will obtain the same rent and other economic benefits that a landlord would otherwise give in a comparable transaction and that Landlord will make and receive the same economic payments and concessions that other landlords would otherwise make and receive in comparable transactions.

(a)

During the Term, Tenant shall not make structural exterior alterations to the Premises (including, without limitation, alterations to the MEP systems serving the Building ( Structural Alterations ) without Landlord’s prior written consent, which consent shall not be unreasonably withheld. Tenant must provide Landlord with a complete set of plans for any proposed Structural Alterations. Tenant shall construct all Structural Alterations in substantial accordance with the approved plans. Notwithstanding the preceding, Tenant will have the right, without Landlord’s consent, to make non-structural alterations ( Non-Structural Alterations ) to the interior of the Premises. In making any Structural Alterations,

Tenant shall notify Landlord at least 30 days prior to commencement of construction; and in making any Structural or Non-Structural Alterations, Tenant shall comply with all Legal Requirements and perform same in a good and workmanlike manner. Tenant shall promptly deliver to Landlord complete and accurate as-built plans for any Structural Alterations. In the event that Tenant’s Non-Structural Alterations consists of moving interior partitions, Tenant shall so notify Landlord; upon Landlord’s written request, Tenant shall provide as-built plans for the relocation of such interior partitions.

(b)

Tenant’s trade fixtures, furnishings and equipment in the Premises will remain Tenant’s property for all purposes and Tenant may remove them at its option and expense at any time on or before the Expiration Date. Upon the expiration of the Term or any earlier termination of this Lease, Tenant shall surrender the Premises in good condition and repair, except for ordinary wear and tear, casualty damage, and damage that Landlord has the obligation to repair under the terms of this Lease. The foregoing covenant does not obligate Tenant to remove Structural or Non-Structural Alterations or other leasehold improvements made with respect to the Premises. All Tenant Improvements and other property of Tenant not timely removed from the Premises shall become part of the Premises and will remain with the Premises upon the expiration of the Term or any earlier termination of this Lease.

(c)

Tenant shall defend, indemnify and save harmless Landlord against any and all mechanic’s and other liens filed arising out of any work performed, materials furnished or obligations incurred in connection with Structural or Non-Structural Alterations. If Tenant does not procure the satisfaction or discharge of all liens for which Tenant is responsible hereunder as and when required by this Lease, by bonding, payment or otherwise Landlord may, upon 30 days’ prior written notice to Tenant, pay the amount of any lien or discharge the same by deposit or, alternatively, by bond or in any manner according to law, together with reasonable expenses incurred by Landlord, including all reasonable legal fees and such expenses shall be payable by Tenant as additional rent hereunder within 30 days after demand.

(a)

During the Term, Landlord shall maintain only the following in good condition at its expense: the structure of the Building, including, without limitation the roof, roof membrane, foundation, floor slab, and load-bearing and exterior walls (the Structural Components ). If, in order for a Structural Component of the Building to remain in good condition, replacement of that component becomes necessary, Landlord’s obligation with respect to that Structural Component includes the obligation to replace it.

(b)

Landlord shall accomplish all maintenance for which it is responsible as soon as practicable following receipt of notice from Tenant. If a hazardous or emergency situation exists, however, Landlord shall have the maintenance performed as soon as possible.

(c)

Except as otherwise provided in this Lease, Tenant shall during the Term maintain in good condition and repair at all times at its expense the Premises and

the systems serving the Premises. Moreover, during the entire Term, Tenant must keep the parking areas clean and in good condition and repair, water the landscape plantings situated on the Land at suitable intervals, and maintain in force service contracts providing for the routine repair and maintenance of the HVAC and other Building systems serving the Premises (each, a Maintenance Contract ). Promptly after receipt thereof, Tenant shall furnish to Landlord a copy of each Maintenance Contract (and each renewal thereof) and a copy of each service report received by Tenant under any Maintenance Contract. Tenant’s obligations include necessary replacements of the landscaping, parking areas, driveways, sidewalks, stairs, elevators, loading dock, dock door, and leveler, and related facilities, and the HVAC and other systems serving the Premises and all Tenant Improvements.

(A)

Tenant must give Landlord written notice of the need for the HVAC Replacement at least 30 days prior to commencing the HVAC Replacement, which notice must include:

(B)

Landlord must give its prior written consent to the HVAC Replacement and the HVAC provider who will install the HVAC Replacement, which consent may not be unreasonably withheld, conditioned, or delayed.

out-of-pocket cost incurred by Tenant for the HVAC Replacement by a fraction whose denominator is the useful life ( Useful Life ) of the HVAC Replacement, as determined in accordance with generally accepted accounting principles (stated in years), and whose numerator is the Useful Life minus the number of full or partial years remaining in the Initial Term or Renewal Term, as applicable, at the time such HVAC Replacement occurs (plus simple interest on the portion of the HVAC Replacement for which Landlord is responsible at the rate of eight percent (8%) per annum from the date that the HVAC Replacement expense was incurred), subject to the following conditions:

E.G., if we assume that Tenant makes an HVAC Replacement at any time during the last year of the Initial Term, Tenant is entitled to reimbursement under this Subsection 8(c)(ii), the Useful Life is determined to be nine years, and the cost of the HVAC Replacement is $500,000, then Landlord’s reimbursement to Tenant will be $444,444 [$500,000 times 8/9], plus simple interest at the rate of eight percent (8%) per annum on the portion of the HVAC Replacement for which Landlord is responsible from the date that the HVAC Replacement expense was incurred.

(iii)

If Landlord consents to an HVAC Replacement at any time during the last two (2) years of the Initial Term or any Renewal Term (or if Landlord does not consent to the HVAC Replacement, Tenant elects to proceed with the HVAC Replacement and to submit its HVAC Replacement Decision for arbitration under Section 41, and the arbitrator decides in favor of Tenant) and Tenant thereafter exercises its Option for an available Renewal Term or Renewal Terms, then at the expiration of the last of such exercised Renewal Terms, Landlord shall reimburse Tenant an amount determined by multiplying the out-of-pocket cost incurred by Tenant for the HVAC Replacement by a fraction whose denominator is the Useful Life of the HVAC Replacement and whose numerator is the Useful Life minus the number of full or partial years which have elapsed since the time the HVAC Replacement occurred plus interest at the rate of eight percent (8%) per annum on the portion of the HVAC Replacement for which Landlord is responsible from the date that the HVAC Replacement expense was incurred.

(a)

Subject to Section 12(b), if (i) Tenant is not in default beyond all applicable grace, notice and cure periods in respect of the performance of its obligations arising under the terms of this Lease, (ii) this Lease is in full force and effect in accordance with its terms, (iii) the Initial Term has not been terminated, (iv) the total stockholder equity of Guarantor (as defined in Section 38) is not less than $500 Million, and (v) its ratio of current assets to current liabilities is not less than 1.0 (taking into account available proceeds under any credit facility in place at the time in question), then Tenant has the option (the Expansion Option ) to lease an addition to the Building (the Expansion ) that Landlord will erect in order to enlarge the floor area of the Building. For purposes of calculating the Guarantor’s total stockholder equity and current ratio, its most recent published annual report or 10Q on file with the Securities and Exchange Commission shall be used.

(b)

If Tenant exercises the Expansion Option during the first Lease Year, the Expansion must be for at least 20,000 rentable square feet, the Annual Base Rent for the Expansion will be the same as the Annual Base Rent (on a per square foot basis) for the initial Premises, the term for the Expansion shall end conterminously with the term of the lease for the Initial Premises and all other terms of this Lease will remain the same.

(c)

If Tenant exercises the Expansion Option after the first Lease Year, the initial Term for the initial Premises will automatically be extended so that the initial Term with respect to the initial Premises and the Expansion are coterminous and last for 12 years from the Expansion Commencement Date (as defined below). Other than the Base Rent, the terms of this Lease with respect to the initial Premises during the balance of the 12-year term will remain as stated in this Lease. The Base Rent payable by Tenant with respect to the initial Premises will remain in effect until the Expiration Date for the Expansion, with the Annual Base Rent increasing by 6.12% on the first day of the 13 ^th Lease Year (based in the initial Term) and on the first day of each succeeding fourth Lease Year (i.e., 16 ^th , 20 ^th , etc.).

(d)

If Tenant exercises the Expansion Option for an Expansion which would exceed 25,000 rentable square feet, then:

Landlord’s sole opinion, marketable to a replacement tenant or tenants. If this Subsection 12(d)(i) is applicable, then Landlord shall promptly so notify Tenant. Notwithstanding the foregoing, if Landlord notifies Tenant that Subsection 12(d)(i)(y) is applicable, then Tenant may notify Landlord within 10 business days after receipt of Landlord’s notice that Tenant elects to reduce the size of the Expansion to 25,000 rentable square feet or less and Landlord will proceed with the construction of the Expansion under this Section 12.

(ii)

If Subsection 12 (d)(i) is not applicable, then Landlord shall notify Tenant of the parking ratio which it will provide for such Expansion and the overall parking ratio for the Building, as expanded; and Tenant may elect to reduce the size of such Expansion after review of such parking ratios.

(i)

The parties will promptly enter in good faith into an agreement whereby (x) Landlord agrees to construct the Expansion within 12 months or less after the execution of such agreement, (y) the parties agree to increase the Base Rent for the Expansion in the manner as set forth in this Section 12, payable during the period from the date Landlord substantially completes construction of the Expansion (the Expansion Commencement Date ) and that ends at 11:59 p.m. (Dallas, Texas local time) on either the day prior to the 12th anniversary of the Expansion Commencement Date, if the Expansion Commencement Date occurs on the first day of a calendar month, or on the day prior to the 12th anniversary of the first day of the first full month following the calendar month in which the Expansion Commencement Date occurs, if the Expansion Commencement Date does not occur on the first day of a month, whichever is applicable (the Expansion Term ).

(ii)

Landlord shall construct the Expansion on the same terms as for the construction of the Landlord Improvements (except for Base Rent as specified in this Section 12), granting Tenant the same Tenant Allowances included in this transaction (on a per rentable square foot basis), except as otherwise specified in Exhibit D .

(iii)

If Tenant exercises the Expansion after the first Lease Year, the Base Rent for the Expansion will be the amount determined by multiplying the Expansion Construction Costs by the sum of (A) the interest rate on 10-year U.S. Treasury Bills as of the Expansion Commencement Date plus (B) 400 basis points. Within 30 days following Landlord’s substantial completion of the construction of the Expansion, Landlord shall furnish to Tenant a detailed itemization of the costs by major construction trade (the Expansion Construction Costs ) that Landlord incurred in connection with the design and construction of the Expansion and copies of invoices, statements, contracts, subcontracts, and other information th