Exhibit 10.5

PAETEC CORP.

SENIOR OFFICER CONFIDENTIALITY, NON-SOLICITATION, NON-

COMPETITION AND SEVERANCE AGREEMENT

This Senior Officer Confidentiality, Non-Solicitation, Non-Competition and
Severance Agreement (this “Agreement”) is entered into as of the date set forth
on the signature page hereto between PaeTec Corp., a Delaware corporation,
including any and all subsidiaries and affiliates of PaeTec Corp., including but
not limited to PaeTec Communications, Inc., as well as any successors or assigns
of PaeTec Corp. and/or its subsidiaries and affiliates (collectively, the
“Company”), and (“you”).

WHEREAS, the Company now has and expects to develop confidential and proprietary
materials and highly sensitive information of immeasurable value, which you
recognize must be carefully protected as set forth below for the Company to be
successful;

NOW, THEREFORE, to induce the Company to continue to employ you, and in
consideration of your continued employment by the Company and other good and
valuable consideration as set forth below of which you expressly acknowledge,
the Company and you hereby agree, intending to be legally bound, as follows:

 

1. Defined Terms.

For purposes of this Agreement, termination for “Cause” shall mean termination
of your employment with the Company due to: (1) material failure or refusal to
perform the duties assigned to you, provided that the Company’s Chief Executive
Officer (or the Company’s Board of Directors if you are the Company’s Chief
Executive Officer) gives you a written notice of your refusal to perform such
duties or comply with such direction and 20 days to remedy such refusal, and
further provided that such duties or directions are not inconsistent with those
of other individuals reporting directly to the Company’s Chief Executive Officer
or the Company’s Board of Directors, (2) your refusal to follow the reasonable
directives of the Board of Directors or Chief Executive Officer of the Company,
provided that the Company’s Chief Executive Officer (or the Company’s Board of
Directors if you are the Company’s Chief Executive Officer) gives you a written
notice of your refusal to perform such direction and 20 days to remedy such
refusal, and further provided that such directions are not inconsistent with
those of other individuals reporting directly to the Company’s Chief Executive
Officer or the Company’s Board of Directors, or (3) conviction of a felony.

For purposes of this Agreement, a “Change of Control Transaction” shall be
deemed to have occurred if (a) a transaction is made and consummated involving
the sale of all or substantially all of the Company’s assets, or the sale of a
majority of its outstanding shares, whether by way of merger, consolidation,
business combination or otherwise; or (b) a tender offer or exchange offer is
made and consummated in a transaction for the ownership of securities of the
Company representing more than 50 percent of the combined voting power of the
Company’s then outstanding voting securities.

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For purposes of this Agreement, “Disability” means your “permanent and total
disability” within the meaning of Section 22(e)(3) of the Internal Revenue Code
of 1986, as now in effect or as hereafter amended.

For purposes of this Agreement, termination for “Good Reason” shall mean
termination of your employment with the Company due to: (a) your assignment
without your consent to a position, responsibilities, or duties of a materially
lesser status or degree of responsibility than your position, responsibilities,
or duties as of the date of this Agreement; (b) any action by the Company to
reduce your base salary by any amount at any time; (c) any action by the Company
to reduce your maximum annual bonus opportunity below 50% of your base salary,
unless any such reduction is made on the same terms as proportionate reductions
to the maximum annual bonus opportunity of the chief financial officer and chief
operating officer; (d) the relocation of the Company’s principal executive
offices outside the metropolitan Rochester, N.Y. area; (e) the requirement by
the Company that you be based anywhere other than your current metropolitan
location without your consent (which current metropolitan area is deemed to be
metropolitan Rochester, N.Y.); or (f) you electing, for any reason or for no
reason at all, to voluntarily resign from the Company at any time during the
first ninety (90) days after the date of closing of any Change of Control
Transaction (as that term is defined above); provided that, solely for purposes
of clause (f) of this definition, the consummation of the transactions
contemplated by the Agreement and Plan of Merger, dated as of August 11, 2006,
as amended, among the Company, US LEC Corp., WC Acquisition Holdings Corp., WC
Acquisition Sub U Corp. and WC Acquisition Sub P Corp. (the “Merger Agreement”),
shall not be deemed to constitute a Change of Control Transaction.

 

2. Confidentiality.

You acknowledge that you will be provided access to Company Confidential
Information and will occupy a position of trust and confidence with respect to
the Company’s affairs and business. “Company Confidential Information” includes,
but is not limited to, all information and materials related to existing
computer software and hardware, computer software and hardware in any stage of
research and development, research, business procedures and strategies,
marketing plans and strategies, customer lists, financial data, technical and
laboratory data and/or specifications related to the Company’s products and
services, and any other information that is not generally known to the public or
within the industry in which the Company competes.

You agree to take all reasonable steps to preserve the confidential and
proprietary nature of Company Confidential Information and to prevent the
inadvertent or accidental disclosure of Company Confidential Information. You
agree that during your employment with the Company and thereafter, you will not
use, disclose, transfer, or remove from the Company’s premises any Company
Confidential Information other than as authorized by the Company. You agree to
return to the Company all Company Confidential Information and copies thereof at
any time upon the request of the Company. Your obligations under this section
entitled “Confidentiality” shall continue after termination of your Service to
the Company.

You further agree not to disclose to the Company or use in the Company’s
business any idea, invention, work of authorship or other information or
material relating to the business of any third person and intended by that
person not to be disclosed to the Company.

 

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3. Non-Competition.

For a period of two years after termination or resignation of your employment
with the Company (regardless of the reason for your termination or resignation),
you shall not, directly or indirectly:

 

  a. solicit or serve clients, customers, or employees of the Company, whether
for your own account or as an employee, shareholder, partner, officer, member,
manager, director, consultant, or other representative of any third party
engaged in the competitive local exchange telecommunications services business,
in any geographical area in which the Company is then conducting operations;

 

  b. direct any business from, or enter into competition with, the Company in
any line of business in which the Company is then conducting operations (in any
geographical area in which the Company is then conducting such line of
business), provided that such line of business is one from which the Company is
generating more than ten percent (10%) of its total business revenues on a
consolidated basis; or

 

  c. serve as an employee, partner, ten percent (10%) or greater shareholder,
officer, member, manager, director, consultant or other representative of any
entity engaged in the activities restricted by subparagraphs “a.” or “b.” above.

The foregoing covenants and agreements in this section entitled
“Non-Competition” and the section entitled “Confidentiality” reflect the entire
understanding and agreement between you and the Company on these subjects, and
by your execution of this Agreement you agree that such covenants and agreements
shall be deemed to supersede any prior discussions, negotiations, or agreements,
whether written or oral, between you and the Company with respect to these
subjects.

 

4. Consideration.

As consideration for the non-competition covenant set forth in Section 3 above,
the Company agrees that, unless your employment is terminated (i) due to your
death or Disability, (ii) for Cause or (iii) due to your voluntary resignation,
the Company shall:

 

  a. pay you during each year of the two-year period in which the covenant is in
effect an amount equal to the highest annualized base salary paid to you at any
time during the one-year period immediately preceding the termination or
resignation of your employment (hereafter referred to as your “Base Salary”),
provided, however, that if you terminate your employment at any time for Good
Reason, or if your employment is terminated by the Company at any time within
one year of the closing of any Change of Control Transaction, then the Company
shall pay you during each year of the two-year period in which the covenant is
in effect an amount equal to two (2) times your Base Salary;

 

  b.

continue, during the entire two-year period in which the non-competition
covenant is in effect, your eligibility and participation in any and all benefit

 

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programs available generally to the Company’s employees, including but not
limited to continuing to cover you and your family under the Company’s
applicable group health plan as if you were an active employee;

 

  c. count the two-year period during which the non-competition covenant is in
effect as two years of service for purposes of calculating the vested portion of
any Company stock options that have been granted to you; and

 

  d. pay you during each year of the two-year period in which the covenant is in
effect an annual bonus amount equal to the greater of (a) forty percent (40%) of
your Base Salary, or (b) the maximum amount that you would have been eligible to
receive under that year’s Company bonus plan as if the bonus year had been
completed and all applicable bonus targets had been exceeded at the highest
levels, and as if you had been an employee of the Company during the entire
applicable bonus year (i.e., the payment shall not be pro-rated in any manner).
Any requirements of the bonus plan that you be employed by the Company during
all of the calendar year covered by the bonus plan and/or be on the payroll as
of the date the bonus payments are actually paid out are expressly waived for
you in this circumstance.

Payment of your Base Salary shall be made in accordance with the Company’s
customary payroll practices. In those years in which you are entitled to receive
two times your annualized Base Salary, the Company shall simply double each
regular payroll payment that is due to you.

Payment of the annual bonus amounts pursuant to subparagraph “d.” above shall be
made in accordance with the Company’s customary annual bonus payout practices.
Payment shall be made to you at the same time and in the same manner as the
annual bonus is paid out to the Company’s employees generally, except that in
any year in which there is no bonus payout to employees generally, the annual
bonus amount due to you pursuant to subparagraph “d.” above shall be paid to you
in full no later than February 1 of the calendar year immediately following the
applicable bonus year.

Continued payment of your Base Salary, your continuation in the Company’s
benefits programs, the continued vesting of your stock options, and the payment
to you of the forty percent bonus or the bonus under the Company’s bonus
program, all under this Section 4, shall not occur if your employment is
terminated (i) due to your death or Disability, (ii) for Cause or (iii) due to
your voluntary resignation, unless, in the case of continued vesting of your
stock options, the terms of your stock options expressly provide for continued
vesting.

If the Company successfully obtains a final judicial determination from a court
of competent jurisdiction that you have in fact violated the terms of the
non-competition covenant set forth in Section 3 above, the Company, in addition
to any other remedies available under law, may discontinue any payments being
made to you pursuant to this Section 4, and may discontinue any continuing
vesting of stock options that would otherwise occur pursuant to this Section 4.
If the Company commences any type of legal proceeding against you to enforce any
provision of this Agreement but does not prevail in that proceeding, the Company
shall, immediately upon receipt of an itemized listing from you, reimburse you
for all of your actual expenses incurred in defending such proceeding, including
attorneys fees and court costs.

 

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Notwithstanding anything in this Agreement to the contrary, if you are a “key
employee” within the meaning of Section 409A of the Internal Revenue Code of
1986, as amended (“Section 409A”), payments under this Agreement shall not
commence (or be made in the case of a lump sum payment) until six months
following your separation from service to the extent necessary to avoid the
imposition of the additional 20% tax under Section 409A (and, in the case of
installment payments, the first payment shall include all installment payments
required by this subsection that otherwise would have been made during such six
month period).

 

5. Retention Rights.

Nothing in this Agreement gives you the right to be retained by the Company in
any capacity. The Company reserves the right to terminate your Service at any
time and for any reason.

 

6. Applicable Law.

This Agreement and its terms will be construed, enforced, and governed by the
laws of the State of Delaware without regard to conflict or choice of law rules
or other principles that might otherwise refer construction or interpretation of
this Agreement to the substantive law of a jurisdiction other than Delaware.

 

7. Forum Selection.

At all times each party hereto (a) irrevocably submits to the exclusive
jurisdiction of any New York court or Federal court sitting in New York;
(b) agrees that any action or proceeding arising out of or relating to this
Agreement or the transactions contemplated hereby shall be heard and determined
in such New York or Federal court; (c) to the extent permitted by law
irrevocably waives (i) any objection such party may have to the laying of venue
of any such action or proceeding in any of such courts, or (ii) any claim that
such party may have that any such action or proceeding has been brought in an
inconvenient forum; and (d) to the extent permitted by law irrevocably agrees
that a final nonappealable judgment in any such action or proceeding shall be
conclusive and may be enforced in other jurisdictions by suit on the judgment or
in any other manner provided by law. Nothing in this section entitled “Forum
Selection” shall affect the right of any party hereto to serve legal process in
any manner permitted by law.

 

8. Entire Agreement.

This Agreement constitutes the entire understanding between you and the Company
regarding the matters addressed in this agreement. Any prior agreements,
commitments or negotiations concerning these matters are hereby superseded.

From and after the Effective Time (as defined in the Merger Agreement), all
rights and obligations of the Company under this Agreement shall be deemed to be
rights and obligations of WC Acquisition Holdings Corp., provided that WC
Acquisition Holdings Corp. assumes such rights and obligations pursuant to the
Merger Agreement or otherwise assumes such rights and obligations prior to such
Effective Time.

 

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By your signature below, you acknowledge that you have reviewed this Agreement
carefully and understand that the covenants and obligations it contains are
binding on you.

[signature page follows]

 

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IN WITNESS WHEREOF, the parties hereto have executed and delivered this Senior
Officer Confidentiality, Non-Solicitation, Non-Competition and Severance
Agreement as of the 27th day of February, 2007.

 

EMPLOYEE

Signature:

 

/s/ Charles E. Sieving

Printed Name:

  Charles E. Sieving

Home Address:

  1619 34th St., N.W., Washington, DC 20007

 

PAETEC CORP.

By:

 

/s/ Arunas A. Chesonis

Name:

  Arunas A. Chesonis

Title:

  President & Chief Executive Officer

 

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