EXHIBIT 10.6

SPECIAL BONUS AGREEMENT

THIS SPECIAL BONUS AGREEMENT (this "Agreement") is by and between Allegiance Telecom Company Worldwide (the "Company") and Mark B. Tresnowski (the "Employee"),
effective as of the date set forth under the signature of the Company below.

NOW,
THEREFORE, in consideration for the promises and mutual covenants herein contained, it is hereby agreed by the parties as follows:

1.SPECIAL BONUS PAYMENT.Employee will be entitled to an aggregate special bonus equal
to $300,000 (the "Bonus Payment"), provided that Employee has been continuously employed by the Company or any Affiliate through December 31, 2003 and subject to the other terms and conditions
of this Agreement. The entire Bonus Payment will be paid to Employee on March 14, 2003.

2.TERMINATION OF EMPLOYMENT.



3.NO SPECIAL EMPLOYMENT RIGHTS.Nothing in this Agreement will (a) be deemed to
confer on Employee any right to employment or continued employment with the Company or any Affiliate, or (b) affect any right that the Company or any Affiliate may have to terminate the
employment of Employee at any time.

4.OTHER EMPLOYEE BENEFITS.No payments made hereunder shall be includible as an annual
or long-term bonus or other compensation in creditable compensation in computing benefits under any employee benefit plan of the Company or any Affiliate.

5.WITHHOLDINGS.The Company may withhold from all payments due to Employee (or his/her
beneficiary or estate) hereunder all taxes or other amounts which, by applicable federal, state, local or other law, the Company is required to withhold therefrom.

6.RIGHT TO WITHHOLD FROM PAYCHECK.In the event Employee is required to repay any Net
Bonus Payment, Employee authorizes the Company and its Affiliates to deduct any amount of such payment from any salary, bonus, vacation pay, commissions or any other compensation earned by Employee
and Employee specifically authorizes the Company and its Affiliates to deduct any amount of such payment from Employee's paycheck(s), including Employee's final paycheck (to the extent lawful). Any
such deductions shall not relieve Employee of his/her obligation to pay any remaining amounts owing under this Agreement.Consent to such deduction(s) shall be evidenced by
Employee's signature on this Agreement.

7.CONFIDENTIAL INFORMATION.Employee shall keep the existence and contents of this
Agreement in strictest confidence and shall not disclose it to anyone other than Employee's tax and financial advisors, attorneys and immediate family members, provided that Employee advises such
persons that the information is confidential. Employee may discuss this Agreement with the Company's Human Resources or Legal departments or the head of Employee's department.

8.DEFINITIONS.As used in this Agreement, the following terms shall have the respective
meanings set forth below:



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9.SUCCESSORS; BINDING AGREEMENT.(a) This Agreement is personal to Employee and
without the prior written consent of the Company, shall not be assignable by Employee otherwise than by will or the laws of descent and distribution. This Agreement shall inure to the benefit of and
be enforceable by Employee's legal representatives. (b) This Agreement shall inure to the benefit of and be binding upon the Company and its successors. The Company agrees that, for so long as
it has any obligations under this Agreement, it will cause any successor or transferee (if other than the Company) to unconditionally assume, by written instrument delivered to Employee (or his/her
beneficiary or estate), all of the obligations of the Company hereunder.

10.NOTICES.All notices, demands or other communications to be given or delivered under
or by reason of the provisions of this Agreement shall be in writing and shall be deemed to have been given when personally delivered or on the fifth day after being sent via U.S. certified or
registered mail, return receipt requested:



or
to such other address or to the attention of such other person as the recipient party has specified by prior written notice to the sending party. Notwithstanding anything herein to the contrary,
the Company may provide Employee with written notice by sending Employee an email.

11.GOVERNING LAW; VALIDITY.The validity, interpretation, and enforcement of this
Agreement shall be governed by the laws of the State of Texas as to all matters, including, but not limited to, matters of validity, construction and performance, without regard to principles of
conflict of laws. Whenever possible, each provision of this Agreement shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Agreement is
held to be invalid, illegal or unenforceable in any respect under any applicable law or rule in any jurisdiction, such invalidity, illegality or unenforceability shall not affect any other provision
or any other jurisdiction, but this Agreement shall be reformed, construed and enforced in such jurisdiction as if such invalid, illegal or unenforceable provision had never been contained herein.

12.CONSENT TO JURISDICTION; AGENT FOR SERVICE OF PROCESS; LIMITATION OF LIABILITY.Employee consents to the non-exclusive jurisdiction and venue in the state and federal courts located in Dallas County, Texas and waives any defense of forum non conveniens.
Service of legal process on the Company with respect to a claim under this Agreement shall be made upon the General Counsel of Allegiance Telecom, Inc. IN NO EVENT SHALL THE COMPANY OR ANY
AFFILIATE BE LIABLE UNDER OR RELATING TO THIS AGREEMENT FOR ANY AMOUNT IN EXCESS OF THE BONUS PAYMENT. NOTWITHSTANDING ANY OTHER PROVISION HEREOF, THE COMPANY SHALL NOT BE LIABLE FOR ANY INDIRECT,
INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY OR PUNITIVE DAMAGES.

13.INTEREST; PAYMENT OF COLLECTION FEES.Employee agrees to repay all amounts due under
this Agreement to the Company within ten (10) days of Employee's termination date. Any amounts due to the Company under this Agreement and not paid shall accrue interest at 1.5% per month (or
if less, the maximum rate permissible under law) starting from the 11th day after Employee's termination date until paid. Employee agrees to pay all of Company's costs of collection
relating to or in connection with this Agreement, including reasonable attorneys' fees.

14.WAIVER.Employee's or the Company's failure to insist upon strict compliance with
any provision hereof or any other provision of this Agreement or the failure to assert any right Employee or the Company may have hereunder shall not be deemed to be a waiver of such provision or
right or any other provision or right of this Agreement.

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15.ENTIRE AGREEMENT; NO AMENDMENT.This Agreement contains the entire agreement and
supersedes all prior and contemporaneous oral or written communications and agreements between the parties relating to the subject matter of this Agreement. Neither this Agreement, nor any of its
terms, may be changed, added to, amended, waived or varied except in writing signed by Employee and by either the CEO, CFO or COO of the Company.

16.COUNTERPARTS; DELIVERY BY FACSIMILE.This Agreement may be executed in counterparts,
each of which shall be deemed to be an original and all of which together shall constitute one and the same instrument. This Agreement any amendments hereto to the extent signed and delivered by means
of a facsimile machine, will be treated in all manner and respects as an original agreement and will be considered to have the same binding legal effect as if it were the original signed version
thereof delivered in person. At the request of any party, each other party hereto will reexecute original forms thereof and deliver them to all other parties. No party hereto will raise the use of a
facsimile machine to deliver a signature or the fact that any signature or agreement or
instrument was transmitted or communicated through the use of a facsimile machine as a defense to the formation or enforceability of a contract and each such party forever waives any such defense.

IN
WITNESS WHEREOF, the parties hereto have executed this Agreement as of the dates set forth below.

BY SIGNING BELOW, EMPLOYEE ACKNOWLEDGES THAT HE/SHE HAS (A) READ THIS AGREEMENT; AND (B) UNDERSTANDS THE TERMS AND CONDITIONS OF THIS AGREEMENT.

|ALLEGIANCE TELECOM COMPANY WORLDWIDE | 
|------------------------------------ | 
|By:                                  | 
|Name:                                | 
|Its:                                 | 
|Effective Date:                      | 
|EMPLOYEE:                            | 
|Printed Name:                        | 
|Date:                                | 

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