Document:

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                       PREFERRED STOCK PURCHASE AGREEMENT

                                  by and among

                                  US LEC CORP.

                                       and

                the Persons listed on Schedule 1 attached hereto

                           Dated as of April 11, 2000
                      ------------------------------------

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                                TABLE OF CONTENTS
                                                                            Page
ARTICLE I  DEFINITIONS.........................................................1
   1.1   Definitions...........................................................1
   1.2   Accounting Terms......................................................9

ARTICLE II  PURCHASE AND SALE OF PREFERRED STOCK..............................10
   2.1   Purchase and Sale of the Preferred Stock.............................10
   2.2   Closing..............................................................10

ARTICLE III  CONDITIONS TO THE OBLIGATION OF THE PURCHASERS TO CLOSE..........10
   3.1   Representations and Warranties.......................................10
   3.2   Compliance with this Agreement.......................................11
   3.3   Officer's Certificate................................................11
   3.4   Secretary's Certificate, Good Standing Certificates..................11
   3.5   Transaction Documents................................................11
   3.6   Payment of Fees......................................................11
   3.7   Purchase Permitted by Applicable Laws................................12
   3.8   Opinions of Counsel..................................................12
   3.9   HSR Clearance........................................................13
   3.10     Certificate of Designation........................................13
   3.11     Preferred Stock Certificate.......................................13
   3.12     Required Contractual Consents.....................................13
   3.13     Voting and Tag-Along Agreement....................................13
   3.14     Amendment to Senior Loan Agreement................................13
   3.15     Required Governmental Consents....................................13
   3.16     Regulatory Events.................................................14
   3.17     Amendment of Bylaws...............................................14
   3.18     Option Agreement..................................................14
   3.19     Corporate Governance Agreement....................................14
   3.20     Registration Rights Agreement.....................................14
   3.21     Listing of Shares.................................................14
   3.22     Amendment to Class B Stockholders Agreement.......................14

ARTICLE IV  CONDITIONS TO THE OBLIGATION OF THE COMPANY TO CLOSE..............14
   4.1   Representations and Warranties True..................................15
   4.2   Compliance with this Agreement.......................................15
   4.3   Issuance Permitted by Requirements of Laws...........................15
   4.4   HSR Clearance........................................................15
   4.5   Opinion of Counsel...................................................15
   4.6   Transaction Documents................................................15

ARTICLE V  REPRESENTATIONS AND WARRANTIES OF THE COMPANY......................15
   5.1   Organization and Qualification.......................................15
   5.2   Authority and Authorization..........................................16
   5.3   Execution and Binding Effect.........................................16

                                       i
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   5.4   Governmental Authorizations..........................................16
   5.5   Regulatory Authorizations............................................16
   5.6   Agreements and Other Documents.......................................17
   5.7   Absence of Conflicts.................................................17
   5.8   Financial Statements.................................................17
   5.9   Disclosure...........................................................18
   5.10     Compliance with Material Agreements...............................18
   5.11     Labor Matters.....................................................18
   5.12     Litigation........................................................18
   5.13     Rights to Property................................................19
   5.14     Taxes.............................................................19
   5.16     No Brokerage Fees.................................................20
   5.17     ERISA.............................................................20
   5.18     Intellectual Property.............................................20
   5.19     Environmental.....................................................21
   5.20     Subsidiaries......................................................21
   5.21     Transactions with Affiliates......................................21
   5.22     Capitalization....................................................21
   5.23     Commission Filings................................................22
   5.24     Investment Company; Public Utility Holding Company................22
   5.25     Securities Act....................................................22
   5.26     Books and Records.................................................23
   5.27     Certain Payments..................................................23
   5.28     Year 2000 Compliance..............................................23
   5.29     Trade Relations...................................................23

ARTICLE VI  REPRESENTATIONS AND WARRANTIES OF THE PURCHASERS..................23
   6.1   Authorization; No Contravention......................................23
   6.2   Binding Effect.......................................................24
   6.3   Accredited Investor; Purchase for Own Account........................24
   6.4   Governmental Authorizations..........................................25
   6.5   No Brokers or Finders................................................25
   6.6   Ownership of Company Securities; Voting and Other Agreements.........25

ARTICLE VII  COVENANTS........................................................25
   7.1   HSR Clearance........................................................25
   7.2   Reservation of Shares................................................26
   7.3   PUC Consents.........................................................26
   7.4   Delivery of Financial and Business Information.......................26
   7.5   Access to Properties.................................................27
   7.6   Pre-Closing Covenants................................................27
   7.7   Exclusivity..........................................................27
   7.8   Tax Matters..........................................................28
   7.9   Confidentiality......................................................28
   7.10     Schedule 13D and 13G..............................................29
   7.11     Election of Directors.............................................29

                                       ii
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   7.12     Series C Designation..............................................29
   7.13     Additional Covenant...............................................29

ARTICLE VIII  INDEMNIFICATION; TERMINATION....................................29
   8.1   Indemnification......................................................29
   8.2   Notification.........................................................30
   8.3   Termination..........................................................30

ARTICLE IX  MISCELLANEOUS.....................................................31
   9.1   Claims and Suits Under Section 8.1...................................31
   9.2   Notices..............................................................31
   9.3   Successors and Assigns...............................................33
   9.4   Determinations, Requests or Consents.................................33
   9.5   Counterparts.........................................................33
   9.6   Headings.............................................................33
   9.7   Governing Law........................................................33
   9.8   Severability.........................................................33
   9.9   Rules of Construction................................................34
   9.10     Entire Agreement..................................................34
   9.12     Publicity.........................................................35
   9.13     Further Assurances................................................35

         SCHEDULES

         Schedule 1          -   Closing Purchasers
         Schedule 5.4        -   Governmental Authorizations
         Schedule 5.5        -   Regulatory Authorizations
         Schedule 5.6        -   Agreements and Other Documents
         Schedule 5.7        -   Absence of Conflicts
         Schedule 5.8        -   Financial Statements
         Schedule 5.10       -   Compliance with Material Agreements
         Schedule 5.12       -   Labor Matters and Litigation
         Schedule 5.14       -   Taxes
         Schedule 5.15       -   No Material Adverse Change
         Schedule 5.16       -   Brokerage Fees
         Schedule 5.18       -   Intellectual Property
         Schedule 5.20       -   Subsidiaries
         Schedule 5.21       -   Transactions with Affiliates
         Schedule 5.22       -   Capitalization
         Schedule 5.29       -   Trade Relations
         Schedule 6.5        -   Brokers or Finders

         EXHIBITS

         Exhibit A       -   Form of Certificate of Designation
         Exhibit B       -   Bylaws

                                      iii
<PAGE>

         Exhibit C       -   Form of Corporate Governance Agreement
         Exhibit D       -   Form of Registration Rights Agreement
         Exhibit E       -   Form of Officer's Certificate
         Exhibit F       -   Form of Secretary's Certificate
         Exhibit G       -   Form of Preferred Stock Certificate
         Exhibit H       -   Form of Voting and Tag-Along Agreement
         Exhibit I       -   Form of Amendment to Senior Loan Agreement
         Exhibit J       -   Form of Option Agreement
         Exhibit K       -   Form of Certificate of Designation for Series C
                             Preferred Stock
         Exhibit L       -   Form of Series C Preferred Stock Purchase Agreement
         Exhibit M       -   Additional Covenant

                                       iv
<PAGE>

                       PREFERRED STOCK PURCHASE AGREEMENT

         THIS PREFERRED STOCK PURCHASE AGREEMENT is dated as of April 11, 2000,
by and among US LEC CORP., a Delaware corporation (the "Company"), and the
Persons whose names are set forth on Schedule 1 attached hereto (individually, a
"Purchaser" and collectively, the "Purchasers").

                              STATEMENT OF PURPOSE

         WHEREAS, the Company will designate a new series of its preferred
stock, par value $0.01 per share, which shall be called the Company's Series A
Convertible Preferred Stock (the "Preferred Stock"), which shall be convertible
into shares of the Company's Class A common stock, par value $0.01 per share, in
accordance with the terms of the Company's Certificate of Designation amending
the Company's Restated Certificate of Incorporation in the form attached hereto
as Exhibit A (the "Certificate of Designation");

         WHEREAS, the Purchasers wish to purchase at the Closing (as defined
below), upon the terms and conditions stated in this Agreement, the number of
shares of the Preferred Stock set forth opposite their name on Schedule 1
attached hereto for an aggregate of 200,000 shares of the Preferred Stock to be
purchased by the Purchasers; and

         WHEREAS, the Company and the Purchasers have reached certain agreements
with regard to the foregoing transactions, all upon the terms and conditions
more particularly described herein.

                                    AGREEMENT

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
contained herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

                                    ARTICLE I

                                   DEFINITIONS

         1.1      DEFINITIONS.

         As used in this Agreement, and unless the context requires a different
meaning, the following terms have the meanings indicated:

"AFFILIATE" means, with respect to a Person, (a) any director, executive
officer, general partner, managing member or other manager of such Person, (b)
any other Person (other than a Subsidiary) which directly or indirectly through
one or more intermediaries, controls, or is controlled by, or is under common
control with, such Person and (c) if such Person is an individual, any member of
the immediate family (including parents, spouse and children) of such
individual, any trust whose principal beneficiary is such individual or one or
more members of such individual's immediate family and any Person who is
controlled by any such member or trust. The term "control" means (i) the power
to vote 25% or more of the securities or other equity interests of a Person
having ordinary voting power (on a fully diluted basis), or (ii) the possession,
directly or indirectly, of any other power to direct or cause the direction of
the management and policies of a Person, whether through ownership of voting
securities, by contract or otherwise.
<PAGE>

         "AGREEMENT" means this Preferred Stock Purchase Agreement, as amended
or supplemented from time to time.

         "BUSINESS DAY" means any day other than a Saturday, Sunday or other day
on which commercial banks in New York City, New York or Charlotte, North
Carolina are authorized or required by law or executive order to close.

         "BYLAWS" means the Bylaws of the Company as amended pursuant to Section
3.17 on or prior to the Closing Date and attached hereto as Exhibit B.

         "CERTIFICATE OF DESIGNATION" means the Certificate of Designation of
the Company relating to the Preferred Stock filed with the Secretary of State of
the State of Delaware on or prior to the Closing Date and attached hereto as
Exhibit A, as subsequently amended, supplemented or otherwise modified.

         "CERTIFICATE OF INCORPORATION" means the Restated Certificate of
Incorporation of the Company as in effect on the date hereof and as amended by
the Certificate of Designation.

         "CLASS B COMMON STOCK" means the Company's Class B common stock, par
value $0.01 per share or any other capital stock of the Company into which such
stock is reclassified or reconstituted.

         "CLOSING" has the meaning assigned thereto in Section 2.2.

         "CLOSING DATE" has the meaning assigned thereto in Section 2.2.

         "CLOSING FAILURE" has the meaning assigned thereto in Section 8.3(a).

         "CODE" means the Internal Revenue Code of 1986, as amended, or any
successor statute thereto.

         "COMMISSION" means the United States Securities and Exchange
Commission.

         "COMMON STOCK" means the Company's Class A common stock, par value
$0.01 per share or any other capital stock of the Company into which such stock
is reclassified or reconstituted.

                                       2
<PAGE>

         "COMMUNICATIONS LAW" means any and all of (i) the Telecommunications
Act of 1996, the Communications Act of 1934, any similar or successor federal
statute to either and the rules and regulations of the FCC thereunder; and (ii)
any state law governing the provision of telecommunications services and the
rules and regulations of the PUC, all as the same may be in effect from time to
time.

         "COMPANY" has the meaning assigned thereto in the Preamble.

         "COMPANY INDEMNIFIED PARTY" has the meaning assigned thereto in Section
8.1.

         "COMPANY LIABILITIES" has the meaning assigned thereto in Section 8.1.

         "COMPETITOR" means any Person that is (directly or through one or more
Affiliates) both (i) engaged in the business of providing telecommunication
services offered by the Company and its Subsidiaries that generate at least 25%
of the Company's consolidated revenues as of the date of the Company's most
recent Form 10-K or 10-Q filed with the Commission and the revenues of such
Person attributable to such services exceed $50 million annualized and (ii) a
competitor of the Company operating in at least 25% of the MSAs (Metropolitan
Statistical Areas) in which the Company and its Subsidiaries are operating as of
the time of the proposed Transfer.

         "CONTRACTUAL OBLIGATIONS" means, with respect to a Person, any
provision of any security issued by such Person or of any agreement,
undertaking, contract, indenture, mortgage, deed of trust or other instrument to
which such Person is a party or by which it or any of its property is bound.

         "CORPORATE GOVERNANCE AGREEMENT" means the Corporate Governance
Agreement dated as of the Closing Date among the Company and the Purchasers
listed on the signature pages thereto and attached hereto as Exhibit C.

         "DGCL" has the meaning assigned thereto in Section 2.1.

         "ENVIRONMENTAL LAW" means any federal, state, foreign or local statute,
law, rule, regulation, ordinance, code or rule of common law now or hereafter in
effect and in each case as amended, and any judicial or administrative
interpretation thereof, including any legally binding judicial or administrative
order, consent decree or judgment, relating to the environment, employee, health
and safety or Hazardous Materials, including, without limitation, the
Comprehensive Environmental Response, Compensation and Liability Act of 1980, as
amended, 42 U.S.C. ss. 9601 et seq.; the Resource Conservation and Recovery Act,
as amended, 42 U.S.C. ss. 6901 et seq.; the Federal Water Pollution Control Act,
as amended, 33 U.S.C. ss. 1251 et seq.; the Toxic Substances Control Act, 15
U.S.C. ss. 2601 et seq.; the Clean Air Act, 42 U.S.C. ss. 7401 et seq.; the Safe
Drinking Water Act, 42 U.S.C. ss.ss. 201 & 300f et seq.; the Oil Pollution Act
of 1990, 33 U.S.C. ss. 2701 et seq.; the Emergency Planning and the Community
Right-to-Know Act of 1986, 42 U.S.C. ss. 11001 et seq.; the Hazardous Material
Transportation Act, 49 U.S.C. ss.1801 et seq. and the Occupational Safety and
Health Act, 29 U.S.C. ss. 651 et seq.; and any state and local or foreign
counterparts or equivalents, in each case as amended from time to time.

                                       3
<PAGE>

         "ERISA" means the Employee Retirement Income Security Act of 1974, as
amended.

         "ERISA AFFILIATE" shall mean any corporation, trade or business that
is, along with the Company, a member of a controlled group of corporations or a
controlled group of trades or businesses, as described in Section 414(b) and
414(c), respectively, of the Code or Section 4001 of ERISA.

         "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended.

         "FCC" means the Federal Communications Commission of the United States
of America, and any successor, in whole or in part, to its jurisdiction.

         "FINANCIAL STATEMENTS" has the meaning assigned thereto in Section 5.8.

         "GAAP" means generally accepted United States accounting principles set
forth in the opinions and pronouncements of the Accounting Principles Board of
the American Institute of Certified Public Accountants and statements and
pronouncements of the Financial Accounting Standards Board that are applicable
to the circumstances as of the date of determination.

         "GOVERNMENTAL AUTHORITY" means the government of any nation, state,
city, locality or other political subdivision of any thereof, any entity
exercising executive, legislative, judicial, regulatory or administrative
functions of or pertaining to government, and any corporation or other entity
owned or controlled, through stock or capital ownership or otherwise, by any of
the foregoing.

         "HAZARDOUS MATERIALS" means (i) any petroleum or petroleum products,
radioactive materials, asbestos in any form that is or could become friable,
urea formaldehyde foam insulation, polychlorinated biphenyls, and radon gas;
(ii) any chemicals, materials or substances defined as or included in the
definition of "hazardous substances", "hazardous wastes", "hazardous materials",
"extremely hazardous substances", "restricted hazardous wastes", "toxic
substances", "toxic pollutants", "contaminants" or "pollutants", or words of
similar meaning and effect, under any applicable Environmental Law; and (iii)
any other chemical, material or substance the release of which is prohibited,
limited or regulated by any Environmental Law.

         "INDEBTEDNESS" means as to any Person, at a particular time, (a)
indebtedness for borrowed money or for the deferred purchase price of property
or services in respect of which such Person is liable, contingently or
otherwise, as obligor, guarantor or otherwise, or in respect of which such
Person otherwise assures a creditor against loss, (b) obligations under leases
which shall have been or should be, in accordance with GAAP, recorded as capital
leases in respect of which obligations such Person is liable, contingently or
otherwise, as obligor, guarantor or otherwise, or in respect of which
obligations such Person assures a creditor against loss, (c) obligations of such
Person to purchase or repurchase accounts receivable, chattel paper or other
payment rights sold or assigned by such Person, (d) indebtedness or obligations
of such Person under or with respect to letters of credit, notes, bonds or other
debt instruments (other than letters of credit that are cash collateralized) and
(e) all obligations of such Person under any interest rate swap, cap or collar
agreement or other similar agreement or arrangement designed to alter the risks
of that Person arising from fluctuations in interest rates, in each case whether
contingent or matured.

                                       4
<PAGE>

         "LIEN" means any mortgage, pledge, hypothecation, assignment, deposit
arrangement, encumbrance, lien (statutory or other), priority or other security
agreement of any kind or nature whatsoever (including, without limitation, any
conditional sale or other title retention agreement, any financing or similar
statement or notice filed under the Uniform Commercial Code or any other similar
recording or notice statute, and any lease having substantially the same effect
as any of the foregoing).

         "MATERIAL ADVERSE CHANGE" means a material adverse change in (i) the
business, operations, assets, condition (financial or otherwise) or properties
of the Company and its Subsidiaries, taken as a whole or (ii) the ability of the
Company to perform its obligations, taken as a whole, under the Transaction
Documents.

         "MATERIAL ADVERSE EFFECT" means a material adverse effect upon (i) the
business, operations, assets, condition (financial or otherwise) or properties
of the Company and its Subsidiaries, taken as a whole, or (ii) the ability of
the Company to perform its obligations, taken as a whole, under the Transaction
Documents.

         "MATERIAL CONTROVERSY" means a controversy that arises among the
Company and any of the holders of the Company's outstanding Common Stock in
respect of the purchase of the Preferred Stock pursuant to this Agreement, the
issuance of the Option Agreement, the potential issuance of the Option Preferred
Stock under the Option Agreement, and the proposed issuance and sale by the
Company of up to 25,000 shares of the Company's Series C Convertible Preferred
Stock to some or all of the lenders under the Senior Loan Agreement.

         "MULTIEMPLOYER PLAN" means any "multiemployer plan" within the meaning
of Section 4001(a)(3) of ERISA to which the Company or any ERISA Affiliate
makes, is making or is obligated to make contributions or has made or been
obligated to make contributions.

         "OPTION AGREEMENT" means the Option Agreement dated as of the Closing
Date among the Company and the Purchasers listed in the signature pages thereto
and attached hereto as Exhibit J.

         "OPTION PREFERRED STOCK" means the Series B Convertible Preferred Stock
of the Company or any other capital stock of the Company into which such stock
is reclassified or reconstituted.

         "OPTION STOCK DESIGNATION" means the Certificate of Designation of the
Company relating to the Option Preferred Stock to be filed with the Secretary of
State of the State of Delaware in accordance with the terms and conditions of
the Option Agreement, as subsequently amended, supplemented or otherwise
modified.

         "ORGANIZATIONAL DOCUMENTS" means with respect to a corporation, the
articles of incorporation and by-laws of such corporation; with respect to a
partnership, the certificate of partnership (or limited partnership, as
applicable) and partnership agreement, together with the analogous documents for
any corporate or partnership general partner; and in any case, any other
document governing the formation and conduct of business by such entity.

                                        5
<PAGE>

         "OTHER PROPOSAL" has the meaning assigned thereto in Section 7.8

         "PBGC" means the Pension Benefit Guaranty Corporation established under
Title IV of ERISA or any other governmental agency, department or
instrumentality succeeding to its functions.

         "PERMITTED TRANSFEREE" means (i) any Affiliate of any Purchaser to whom
a Purchaser or another Affiliate of any Purchaser transfers Preferred Stock,
rights under the Option Agreement, or Option Preferred Stock, (ii) any other
Person to whom a Purchaser or an Affiliate of any Purchaser transfers Preferred
Stock, rights under the Option Agreement, or Option Preferred Stock with the
prior written consent of the Board of Directors and (iii) any Person to whom a
transferee described in clause (ii) transfers Preferred Stock, rights under the
Option Agreement, or Option Preferred Stock with the prior written consent of
the Board of Directors and (iv) any THL Holder (as defined in the Corporate
Governance Agreement) and any of the funds affiliated with Bain Capital, Inc.
and any general or limited partner of such funds; provided, however, that in no
event shall any such transferee or proposed transferee under any of clauses (i),
(ii), (iii), or (iv) be a Competitor or Person acting as a representative of a
Competitor. No transfer otherwise permissible shall be effective unless the
Permitted Transferee agrees in writing expressly for the Company's benefit to be
bound by the provisions of this Agreement, and in this event, the transferor
shall not be liable for the transferee's performance of its obligations under
this Agreement.

         "PERSON" means any individual, firm, corporation, partnership, trust,
limited liability company, incorporated or unincorporated association, joint
venture, joint stock company, Governmental Authority or other entity of any
kind, and shall include any successor (by merger or otherwise) of such entity.

         "PLAN" means (i) an "employee pension plan" as defined in Section 3(2)
of ERISA, (ii) an "employee welfare benefit plan" as defined in Section 3(1) of
ERISA or (iii) any other employee benefit or fringe benefit plan or program,
whether established by Requirements of Law, a written agreement or other
instrument, or custom or informal understanding.

         "PREFERRED STOCK" means the Series A Convertible Preferred Stock of the
Company, or any other capital stock of the Company into which such stock is
reclassified or reconstituted.

         "PROXY STATEMENT" has the meaning assigned thereto in Section 7.7.

         "PUC" means the public utilities commission for any state or any other
jurisdiction, or any successor agency, and any successor, in whole or in part,
to its functions or jurisdictions.

         "PURCHASER(S)" has the meaning assigned thereto in the Preamble and
their successors and permitted assigns.

                                       6
<PAGE>

         "PURCHASER PREFERRED STOCK" means the Series A Preferred Stock and the
Option Preferred Stock.

         "PURCHASER REGULATORY EVENT" means any event in which any Purchaser
becomes subject to regulation as a "carrier," a "telephone company," a "common
carrier," a "public utility," or otherwise under any applicable law or
governmental regulation, federal, state or local, as a result of the purchase of
the Preferred Stock pursuant to this Agreement, the assumed purchase of 100,000
shares of Option Preferred Stock pursuant to the Option Agreement at the
Closing, and the execution and delivery of the Transaction Documents by the
parties thereto at the Closing.

         "REGISTRATION RIGHTS AGREEMENT" means the Registration Rights Agreement
dated as of the Closing Date among the Company and the Purchasers listed on the
signature pages thereto and attached hereto as Exhibit D.

         "REGULATION D" means Rule 506 of Regulation D as promulgated by the
Commission.

         "REGULATORY AUTHORIZATIONS" means all approvals, authorizations,
licenses, filings, notices, registrations, consents, permits, exemptions,
registrations, qualifications, designations, declarations, or other actions or
undertakings made by, to or in respect of any telecommunications Governmental
Authority, including any certificates of public convenience and all grants,
approvals, licenses, filings and registrations from or to the FCC or any PUC or
under any Communications Law necessary in order to enable the Company or its
Subsidiaries to provide telecommunications service of the type provided or
proposed to be provided by such entity as of the date hereof.

         "REGULATORY EVENT" means any of the following events: (i) the Company
or any of its Subsidiaries becomes subject to regulation by any Governmental
Authority in any way that is materially different from the regulation existing
at the date hereof and that would reasonably be expected to have a Material
Adverse Effect, or (ii) the FCC or any PUC issues an order revoking, denying or
refusing to renew, or recommending the revocation, denial or non-renewal of, any
Regulatory Authorization that would reasonably be expected to have a Material
Adverse Effect; provided, however, that the term "Regulatory Event" shall not
include (x) any adverse decision by the FCC, any PUC or Governmental Authority
regarding reciprocal compensation for enhanced service provider (including
Internet service provider) telecommunications traffic or the ability of the
Company or any of its Subsidiaries to collect such reciprocal compensation or
(y) the FCC, any PUC or Governmental Authority enacts Requirements of Law which
restrict, prevent or limit the billing, calculation, collection or payment of
reciprocal compensation for enhanced service provider (including Internet
service provider) telecommunications traffic.

         "REPORTABLE EVENT" has the meaning assigned thereto in ERISA for which
notice has not been waived by regulation.

         "REPRESENTATIVES" has the meaning assigned thereto in Section 7.9.

         "REQUIRED HOLDERS" has the meaning assigned thereto in Section 9.4.

                                       7
<PAGE>

         "REQUIREMENTS OF LAW" means, with respect to a Person, the
Organizational Documents of such Person, and any law, treaty, rule, regulation,
right, privilege, qualification, license, permit or franchise or determination
of an arbitrator or a court or the FCC, PUC or other Governmental Authority, in
each case applicable to or binding upon such Person or any of its property or to
which such Person or any of its property is subject or pertaining to any or all
of the transactions contemplated or referred to herein, including all applicable
common law, all provisions of all applicable material state and federal
constitutions, statutes, rules, regulations and orders of all governmental
bodies, all Regulatory Authorizations issued to the Company or its Subsidiaries,
all Communications Laws and all Environmental Laws.

         "SECURITIES ACT" means the Securities Act of 1933, as amended.

         "SENIOR LOAN AGREEMENT" means the Second Amended and Restated Loan and
Security Agreement dated as of December 20, 1999 to which the Company is a party
as a borrower, as amended from time to time in accordance with the terms
thereof.

         "SENIOR LOAN DOCUMENTS" means the Senior Loan Agreement and each other
Loan Document as defined and referred to in the Senior Loan Agreement, as
amended from time to time in accordance with the terms thereof.

         "SERIES C DESIGNATION" means the Certificate of Designation of the
Company relating to the Series C Preferred Stock to be filed with the Secretary
of State of the State of Delaware in the form attached hereto as Exhibit K.

         "SERIES C PREFERRED STOCK" means the Series C Convertible Preferred
Stock of the Company or any other capital stock of the Company into which such
stock is reclassified or reconstituted.

         "SERIES C PREFERRED STOCK PURCHASE AGREEMENT" means the Series C
Preferred Stock Purchase Agreement in the form attached hereto as Exhibit L.

         "STOCK OPTION PLAN" means the 1998 Omnibus Stock Plan of the Company as
in effect on the date hereof, as it may be amended from time to time, and any
and all stock options and other stock-based awards issued pursuant thereto.

         "SUBSIDIARY" means, as to any Person, (i) any corporation more than
fifty percent (50%) of whose stock of any class or classes having by the terms
thereof ordinary voting power to elect a majority of the directors of such
corporation (irrespective of whether or not at the time stock of any class or
classes of such corporation shall have or might have voting power by reason of
the happening of any contingency) is at the time owned such Person and/or one or
more Subsidiaries of such Person and (ii) any partnership, limited liability
company, association, joint venture or other entity in which such Person and/or
one or more Subsidiaries of such Person has more than a 50% equity interest at
the time.

                                       8
<PAGE>

         "TAXES" means all taxes, assessments, fees and other charges levied
upon the properties of the Company and its Subsidiaries as shown upon all
federal, state and local tax returns and reports, U.S. and non-U.S., required to
be filed by such entity.

         "TAX RETURN" means any return (including any information return),
report, statement, form or other document required to be filed with or submitted
to any Governmental Authority in connection with the determination, assessment,
collection or payment of any Taxes.

         "TRANSACTION DOCUMENTS" means, collectively, this Agreement, the
Certificate of Incorporation, the Certificate of Designation, the Option Stock
Designation, the Bylaws, the Corporate Governance Agreement, the Registration
Rights Agreement, the Voting and Tag-Along Agreement and the Option Agreement.

         "UNDERLYING COMMON STOCK" means all shares of Common Stock issued or
issuable upon conversion of (i) the Preferred Stock issued pursuant to this
Agreement and (ii) the Option Preferred Stock actually issued pursuant to the
Option Agreement as of the date of any determination (which number shall be
determined, with respect to any given date, based upon the conversion price with
respect to the Preferred Stock or Option Preferred Stock, as applicable, in
effect as of such date without giving effect to the one year limitation on
conversion) without regard to any preferential dividends that accrue or are
issued or paid with respect to the Preferred Stock pursuant to the Certificate
of Designation or the Option Preferred Stock pursuant to the Option Stock
Designation.

         "UNITED STATES" and "U.S." shall mean the United States of America.

         "VOTING AND TAG-ALONG AGREEMENT" means the Voting and Tag-Along
Agreement dated as of the Closing Date by and among the Purchasers and Richard
T. Aab, Melrich Associates, L.P., Tansukh V. Ganatra and SuperSTAR Associates
Limited Partnership and attached hereto as Exhibit H.

         "YEAR 2000 COMPLIANT" means that the computer systems and switches and
related equipment and software (i) are capable of recognizing, processing,
managing, representing, interpreting, and manipulating correctly date-related
data for dates earlier and later than January 1, 2000, (ii) have the ability to
provide date recognition for any data element without limitation (including, but
not limited to, date-related data represented without a century designation,
date-related data whose year is represented by only two digits and date fields
assigned special values), (iii) have the ability to automatically function into
and beyond the year 2000 without human intervention and without any change in
operations associated with the advent of the year 2000, (iv) have the ability to
correctly interpret data, dates and time into and beyond the year 2000, (v) have
the ability not to produce noncompliance in existing information, nor otherwise
corrupt such data into and beyond the year 2000, (vi) have the ability to
correctly process after January 1, 2000 data containing dates before that date,
and (vii) have the ability to recognize all "leap years," including February 29,
2000.

         1.2 ACCOUNTING TERMS. All accounting terms used herein not expressly
defined in this Agreement shall have the respective meanings given to them in
accordance with sound accounting practice. The term "sound accounting practice"
shall mean such accounting practice as, in the opinion of the independent
certified public accountants regularly retained by the Company, conforms at the
time to GAAP applied on a consistent basis except for changes with which such
accountants concur.

                                       9
<PAGE>

                                   ARTICLE II

                      PURCHASE AND SALE OF PREFERRED STOCK

         2.1 PURCHASE AND SALE OF THE PREFERRED STOCK. Subject to the terms and
conditions hereof, the Company agrees to issue to the Purchasers, and each
Purchaser agrees severally and not jointly to purchase from the Company, on the
Closing Date, the number of shares of the Preferred Stock set forth opposite
such Purchaser's name on Schedule 1 for a purchase price of $1,000 per share for
an aggregate purchase price of $200,000,000. The Preferred Stock shall have the
powers, rights and preferences as set forth in the Certificate of Designation,
which Certificate of Designation will be duly adopted by the Board of Directors
prior to the Closing Date in accordance with the provisions of Section 151 of
the Delaware General Corporation Law of the State of Delaware (the "DGCL") and
will be filed with the Secretary of State of the State of Delaware prior to or
contemporaneously with the Closing Date pursuant to the DGCL. A true and correct
copy of the Certificate of Incorporation of the Company as currently in effect
prior to the adoption and filing of the Certificate of Designation has
heretofore been furnished to the Purchasers by the Company.

         2.2 CLOSING. Subject to the terms and conditions of this Agreement, the
issuance and purchase of the Preferred Stock shall take place at the closing
(the "Closing") to be held at the offices of Moore & Van Allen, PLLC, Charlotte,
North Carolina, at 10:00 a.m., on April __, 2000, or at such other time and
place as the Company and the Purchasers may agree in writing (the "Closing
Date"). At the Closing, the Company shall deliver to the Purchasers certificates
representing the 200,000 shares of the Preferred Stock against delivery to the
Company by the Purchasers of the purchase price therefor by wire transfer of
immediately available funds.

                                   ARTICLE III

             CONDITIONS TO THE OBLIGATION OF THE PURCHASERS TO CLOSE

         The obligation of each Purchaser to purchase the number of shares of
Preferred Stock set forth opposite its name on Schedule 1 at the Closing, to pay
the purchase price therefor at the Closing and to perform any other obligations
hereunder shall be subject to the reasonable satisfaction as determined by each
Purchaser of the following conditions on or before the Closing Date:

         3.1 REPRESENTATIONS AND WARRANTIES. The representations and warranties
of the Company contained in Section 5 hereof shall be true and correct (i) when
made and (ii) on and as of the Closing Date as if made on and as of such date
(except for representations and warranties that speak as of a specific date in
which case the representation or warranty only need be true and correct as of
the specified date).

                                       10
<PAGE>

         3.2 COMPLIANCE WITH THIS AGREEMENT. The Company shall have performed
and complied in all material respects with all of the agreements, obligations,
covenants and conditions set forth in this Agreement or any other Transaction
Document or contemplated herein or therein that are required to be performed or
complied with by the Company on or before the Closing Date.

         3.3 OFFICER'S CERTIFICATE. Each Purchaser shall have received a
certificate dated as of the Closing Date from the chief executive officer and
chief financial officer of the Company, substantially in the form of Exhibit E,
to the effect that (a) all representations and warranties of the Company
contained in this Agreement and the Option Agreement are true and correct, (b)
the Company is not in violation in any material respect of any of the covenants
contained in this Agreement, (c) all conditions precedent to the Closing to be
performed by the Company have been duly performed in all material respects, and
(d) no Material Controversy has occurred prior to Closing.

         3.4 SECRETARY'S CERTIFICATE, GOOD STANDING CERTIFICATES. Each Purchaser
shall have received a certificate from the Company dated the Closing Date and
signed by the Secretary or an Assistant Secretary of the Company, substantially
in the form of Exhibit F, certifying (a) that the attached copies of the
Certificate of Incorporation, Bylaws or other applicable governance documents
and resolutions of the Board of Directors of the Company (i) authorizing the
issuance of the Preferred Stock pursuant to this Agreement, the issuance of the
Option Preferred Stock pursuant to the Option Agreement and the issuance of any
Common Stock upon conversion thereof and (ii) approving this Agreement, each of
the other Transaction Documents and the transactions contemplated hereby and
thereby to which it is a party, are all true, complete and correct and remain
unamended and in full force and effect, (b) as to the incumbency and specimen
signature of each officer of the Company executing this Agreement and the other
Transaction Documents to which it is a party and any other document delivered in
connection herewith or therewith on behalf of the Company and (c) as to the good
standing of the Company and its Subsidiaries in each such company's state of
incorporation.

         3.5 TRANSACTION DOCUMENTS. Each Purchaser shall have received and
approved true, complete and correct copies of the executed Transaction
Documents, each of which will be in full force and effect as of the Closing
Date.

         3.6 PAYMENT OF FEES. There shall have been paid by the Company to Bain
Capital Partners VI, L.P. a funding fee equal to 1% of the amount funded by Bain
Capital CLEC Investors, L.L.C. at the Closing, (b) to Thomas H. Lee Equity
Advisors IV, L.P. a funding fee equal to 1% of the amount funded by all
Purchasers other than Bain Capital CLEC Investors, L.L.C. at the Closing and (c)
to each Purchaser all legal fees and expenses required to be paid or reimbursed
to such Purchaser by the Company pursuant to Section 9.11 hereof. In addition,
the Company shall have paid in full all fees due to First Union Securities, Inc.
in connection with the transactions contemplated by this Agreement as of the
Closing.

                                       11
<PAGE>

         3.7 PURCHASE PERMITTED BY APPLICABLE LAWS. The acquisition of and
payment for the Preferred Stock to be acquired by each Purchaser at the Closing
and the consummation of the transactions contemplated hereby at the Closing (a)
shall not be prohibited by any Requirement of Law, and (b) shall not subject any
Purchaser to any penalty or, in its reasonable judgment, other adverse condition
under or pursuant to any Requirement of Law.

         3.8 OPINIONS OF COUNSEL. The Purchasers shall have received (a) from
Moore & Van Allen, PLLC, special legal counsel for the Company, a favorable
opinion as of the Closing Date, to the effect that: (i) the Company is duly
organized as a corporation under the DGCL; (ii) the Company is validly existing
and in good standing in the jurisdiction of its incorporation and has the
requisite corporate power to own or lease and operate its property, and to carry
on its business as currently conducted; (iii) each of this Agreement and the
other Transaction Documents executed by the Company is a legal, valid and
binding obligation of the Company enforceable in accordance with its terms,
except as enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium, fraudulent conveyance or other similar laws
affecting the enforcement of creditors' rights generally or by general equitable
principles relating to enforceability; (iv) the Company's execution, delivery
and performance of this Agreement and the other Transaction Documents to which
it is a party were duly authorized by all corporate actions required under its
Organizational Documents and the DGCL; (v) the issuance of the Preferred Stock
and Option Preferred Stock, including the issuance of Preferred Stock and Option
Preferred Stock as preferential dividends pursuant to the Certificate of
Designation and the Option Stock Designation, has been duly authorized by all
corporate action required under the Company's Organizational Documents; (vi)
each of the Certificate of Designation and the Option Stock Designation has been
duly authorized by all corporate action required under the Company's
Organizational Documents and the Certificate of Designation has been filed with
the Secretary of State of Delaware; (vii) the execution, delivery and
performance of the Transaction Documents to which the Company is a party will
not (x) violate the Certificate or Bylaws or (y) violate, to such counsel's
knowledge, any order, writ, injunction or decree of any Governmental Authority;
(viii) upon issuance at the Closing, the Preferred Stock will be validly issued,
fully paid and nonassessable, and will not have been issued in violation of or
be subject to any preemptive rights, and the issuance of the shares of Common
Stock issuable upon conversion of the Preferred Stock has been duly authorized
and such shares have been duly reserved for issuance, and upon issuance will be
validly issued, fully paid and nonassessable, and will not have been issued in
violation of or be subject to any preemptive rights; and (ix) upon issuance
pursuant to the terms of the Option Agreement, the Option Preferred Stock will
be validly issued, fully paid and nonassessable, and will not have been issued
in violation of or be subject to any preemptive rights, and the issuance of the
shares of Common Stock issuable upon conversion of the Option Preferred Stock
has been duly authorized and such shares have been duly reserved for issuance,
and upon issuance will be validly issued, fully paid and nonassessable, and will
not have been issued in violation of or be subject to any preemptive rights; and
(b) from Swidler Berlin Shereff Friedman, LLP, special regulatory counsel to the
Company, a favorable opinion as of the Closing Date to the effect that: (i) no
consents or approvals of the FCC or any PUC are required for the purchase of the
Preferred Stock pursuant to this Agreement, the purchase of 100,000 shares of
Option Preferred Stock at the Closing pursuant to the Option Agreement, and the
execution and delivery at the Closing of the Transaction Documents by the
parties thereto; and (ii) neither the execution and delivery of this Agreement
or the Option Agreement by the Company and the Purchasers, the purchase of the
Preferred Stock and the purchase of 100,000 shares of Option Preferred Stock at
the Closing pursuant to the terms thereof, nor the execution and delivery at the
Closing of the other Transaction Documents by the parties thereto, will, in and
of themselves, subject the Purchasers to regulation as common carriers or
telephone companies under the Communications Act (as defined in such opinion) or
State Telecommunications Act (as defined in such opinion) or State
Telecommunications Laws (as defined in such opinion) in those states in which
the Company and its Subsidiaries are certified to operate as of the Closing. For
purposes of the opinion to be delivered pursuant to clause (b), Swidler Berlin
Shereff Friedman, LLP may assume that 100,000 shares of Option Preferred Stock
are purchased under the Option Agreement at the Closing.

                                       12
<PAGE>

         3.9 HSR CLEARANCE. Any required clearance under the Hart-Scott-Rodino
Act to sell the Preferred Stock upon the terms of this Agreement shall have been
obtained.

         3.10 CERTIFICATE OF DESIGNATION. On or prior to the Closing, the
Certificate of Designation shall have been duly filed with the Secretary of
State of the State of Delaware, all in accordance with the applicable provisions
of the DGCL, and the Certificate of Designation shall constitute a legal and
valid amendment of the Certificate of Incorporation and, as of the Closing, the
Certificate of Incorporation shall not have been otherwise amended.

         3.11 PREFERRED STOCK CERTIFICATE. Each Purchaser shall have received
from the Company a duly executed preferred stock certificate, substantially in
the form of Exhibit G, dated the Closing Date representing the number of shares
of Preferred Stock purchased by it at the Closing.

         3.12 REQUIRED CONTRACTUAL CONSENTS. The Company shall have received any
consents required pursuant to the terms of the Senior Loan Agreement or any
other material Contractual Obligation in connection with the execution and
delivery by the Company of this Agreement and the other Transaction Documents
and the consummation of the transactions to be performed by the Company
contemplated by the Transaction Documents.

         3.13 VOTING AND TAG-ALONG AGREEMENT. The Purchasers shall have received
a Voting and Tag-Along Agreement, substantially in the form of Exhibit H, dated
the Closing Date duly executed by all parties thereto.

         3.14 AMENDMENT TO SENIOR LOAN AGREEMENT. Each Purchaser shall have
received a copy of an amendment to the Senior Loan Agreement, substantially in
the form of Exhibit I, duly executed by all parties thereto.

         3.15 REQUIRED GOVERNMENTAL CONSENTS. The Company shall have received
all Regulatory Authorizations and other Governmental Authority approvals or
consents required in connection with the execution and delivery by the Company
of this Agreement and the other Transaction Documents and the consummation of
the transactions to be performed by the Company contemplated by the Transaction
Documents.

                                       13
<PAGE>

         3.16 REGULATORY EVENTS. No Regulatory Event or Purchaser Regulatory
Event shall have occurred and be continuing or shall occur as a result of the
purchase of the Preferred Stock at the Closing.

         3.17 AMENDMENT OF BYLAWS. The Bylaws shall have been amended (i) to
permit the holders of at least 50,000 of the outstanding shares of Purchaser
Preferred Stock to call for a meeting of the Company's stockholders, (ii) to
permit any two directors to call a meeting of the Company's board of directors,
(iii) to establish the size of the Company's board at seven directors, (iv) to
require regular meetings of the Company's board of directors to be held at least
once during each of the Company's fiscal quarters and (v) to provide that no
amendment to the preceding provisions of the Bylaws shall be effective without
the approval of holders of 50,000 of the outstanding shares of Purchaser
Preferred Stock. The Bylaws as so amended shall be in full force and effect as
of the Closing and shall not have been further amended.

         3.18 OPTION AGREEMENT. The Purchasers shall have received an Option
Agreement, substantially in the form of Exhibit J, dated the Closing Date duly
executed by all parties thereto.

         3.19 CORPORATE GOVERNANCE AGREEMENT. The Purchasers shall have received
a Corporate Governance Agreement, substantially in the form of Exhibit C, dated
the Closing Date duly executed by all parties thereto.

         3.20 REGISTRATION RIGHTS AGREEMENT. The Purchasers shall have received
a Registration Rights Agreement, substantially in the form of Exhibit D, dated
the Closing Date duly executed by all parties thereto.

         3.21 LISTING OF SHARES. The Company shall have filed with The Nasdaq
Stock Market notice of the maximum number of shares of Common Stock potentially
issuable pursuant to the terms of the Certificate of Designation and the Option
Stock Designation other than any such shares as may be issuable upon an
adjustment in the conversion price of the Preferred Stock or the Option
Preferred Stock.

         3.22 AMENDMENT TO CLASS B STOCKHOLDERS AGREEMENT. The Purchasers shall
have received, in form and substance reasonably satisfactory to the Purchasers,
the Second Amended and Restated Stockholders' Agreement among the holders of the
Class B Common Stock duly executed by all such holders and in full force and
effect as of the Closing Date.

                                   ARTICLE IV

              CONDITIONS TO THE OBLIGATION OF THE COMPANY TO CLOSE

         The obligations of the Company to issue and sell the Preferred Stock at
the Closing and to perform its other obligations hereunder at the Closing shall
be subject to the satisfaction as determined by the Company of the following
conditions on or before the Closing Date:

                                       14
<PAGE>

         4.1 REPRESENTATIONS AND WARRANTIES TRUE. The representations and
warranties of each of the Purchasers contained in Section 6 hereof shall be true
and correct on and as of the Closing Date as if made on and as of such date.

         4.2 COMPLIANCE WITH THIS AGREEMENT. Each of the Purchasers shall have
performed and complied in all material respects with all of its agreements and
conditions set forth or contemplated herein that are required to be performed or
complied with by each of the Purchasers on or before the Closing Date.

         4.3 ISSUANCE PERMITTED BY REQUIREMENTS OF LAWS. The issuance of the
Preferred Stock to be issued by the Company hereunder at the Closing and the
consummation of the transactions contemplated hereby at the Closing (a) shall
not be prohibited by any Requirement of Law and (b) shall not subject the
Company to any penalty or, in its reasonable judgment, other onerous condition
under or pursuant to any Requirement of Law.

         4.4 HSR CLEARANCE. Any required clearance under the Hart-Scott-Rodino
Act to acquire the Preferred Stock upon the terms of this Agreement shall have
been obtained.

         4.5 OPINION OF COUNSEL. The Purchasers shall have delivered to the
Company an opinion dated the Closing Date, from the Purchasers' counsel, Ropes &
Gray, in form and substance reasonably acceptable to the Company and its
counsel, to the effect that: (i) each Purchaser's execution, delivery and
performance of this Agreement and the other Transaction Documents was duly
authorized by the requisite corporate, fiduciary, limited liability company or
partnership action required under its Organizational Documents and applicable
state law; (ii) the officer, partner, trustee, managing member or managing
director signing this Agreement and all other documents or instruments
contemplated hereby in its name was duly authorized to do so; and (iii) each of
this Agreement and the other Transaction Documents executed by such Purchaser is
a legal, valid and binding obligation of such Purchaser enforceable in
accordance with their respective terms, except as enforceability may be limited
by applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent
conveyance or other similar laws affecting the enforcement of creditors' rights
generally or by general equitable principles relating to enforceability.

         4.6 TRANSACTION DOCUMENTS. The Company shall have received copies of
each of the Transaction Documents duly executed by all parties thereto.

                                    ARTICLE V

                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

         The Company hereby represents and warrants to the Purchasers, after
giving effect to the transactions contemplated by this Agreement and the other
Transaction Documents, as follows:

         5.1 ORGANIZATION AND QUALIFICATION. Each of the Company and its
Subsidiaries is duly organized, validly existing and in good standing under the
laws of its state of organization. Each of the Company and its Subsidiaries is
duly qualified to do business and in good standing in each jurisdiction in which
the failure to receive or retain such qualification would reasonably be expected
to have a Material Adverse Effect. As to any such entity that is a limited
liability company, each manager is duly organized, validly existing, in good
standing under the laws of its state of organization, and duly qualified to do
business and in good standing in each jurisdiction in which the failure to
receive or retain such qualification would reasonably be expected to have a
Material Adverse Effect.

                                       15
<PAGE>

         5.2 AUTHORITY AND AUTHORIZATION. Each of the Company and its
Subsidiaries has all requisite corporate or limited liability company right,
power, authority and legal right to carry on its business, to own or lease its
properties and to execute and deliver and perform its obligations under this
Agreement, and, in the case of the Company, to execute and deliver and to
perform its obligations under the Transaction Documents and consummate the
transactions contemplated by the Transaction Documents. The Company's execution,
delivery and performance of the Transaction Documents and any other documents or
instruments to be delivered pursuant thereto to which it is a party have been
duly and validly authorized by all necessary corporate proceedings on the part
of the Company. Upon issuance, the Preferred Stock, the Option Preferred Stock
and any shares of such stock issuable as preferential dividends pursuant to the
terms thereof, will be validly issued, fully paid and nonassessable, and will
not have been issued in violation of or subject to any preemptive rights, and
the shares of Common Stock issuable upon conversion of the Preferred Stock, the
Option Preferred Stock and any shares of stock issuable as preferential
dividends pursuant to the terms thereof, have been duly authorized and, as of
the Closing, will be reserved for issuance, and upon issuance will be validly
issued, fully paid and nonassessable, and will not have been issued in violation
of or be subject to any preemptive rights.

         5.3 EXECUTION AND BINDING EFFECT. This Agreement and all other
Transaction Documents to which the Company is a party have been or will be duly
and validly executed and delivered by the Company, and constitute or, when
executed and delivered, will constitute, the legal, valid and binding
obligations of the Company enforceable in accordance with their respective
terms, except as such enforceability may be limited by bankruptcy, insolvency,
reorganization, receivership, moratorium or other laws affecting creditors'
rights generally.

         5.4 GOVERNMENTAL AUTHORIZATIONS. Except as set forth on Schedule 5.4,
no authorization, consent, approval, license, exemption or other action by, and
no registration, qualification, designation, declaration or filing with, any
Governmental Authority is or will be necessary in connection with the execution
and delivery of this Agreement or any other Transaction Documents by the
Company, consummation by the Company of the transactions herein or therein
contemplated, performance of or compliance by the Company with the terms and
conditions hereof or thereof or the legality, validity and enforceability hereof
or thereof.

         5.5 REGULATORY AUTHORIZATIONS. Each of the Company and its Subsidiaries
holds all Regulatory Authorizations necessary for the conduct of its business as
now conducted and has conducted its business in substantial compliance with such
Regulatory Authorizations. All such Regulatory Authorizations are in full force
and effect, are subject to no further administrative or judicial review and are
therefore final. The Regulatory Authorizations are listed on Schedule 5.5. No
Regulatory Event has occurred and is continuing and no Regulatory Event will
occur as a result of the consummation of the transactions contemplated by the
Transaction Documents.

                                       16
<PAGE>

         5.6 AGREEMENTS AND OTHER DOCUMENTS. As of the date hereof, the Company
has provided to the Purchasers, accurate and complete copies (or summaries) of
all of the following agreements or documents to which the Company or any of its
Subsidiaries is subject and each of which is listed on Schedule 5.6: (a)
instruments or documents evidencing Indebtedness of the Company or its
Subsidiaries and any security interest granted by the Company or its
Subsidiaries with respect thereto; and (b) instruments and agreements evidencing
the issuance of any equity securities, warrants, rights or options to purchase
equity securities of the Company or its Subsidiaries.

         5.7 ABSENCE OF CONFLICTS. The execution and delivery of this Agreement
and the other Transaction Documents to which the Company is a party, the
consummation by the Company of the transactions herein or therein contemplated
and the performance of or compliance with the terms and conditions hereof or
thereof by the Company will not, directly or indirectly (and with or without
notice or the passage of time or both), (a) violate any Requirements of Law
applicable to the Company or its Subsidiaries; (b) conflict with or result in a
breach of or a default under the Organizational Documents of the Company or its
Subsidiaries or any Contractual Obligation to which the Company or its
Subsidiaries is a party or by which such entity or its properties are bound; (c)
result in the creation or imposition of any Lien upon any property (now owned or
hereafter acquired); or (d) violate or conflict with, or give any Governmental
Authority the right to challenge the transactions contemplated by the
Transaction Documents or revoke, withdraw, suspend, cancel, terminate or modify,
any Regulatory Authorization issued to or held by the Company or any Subsidiary
(other than as set forth on Schedule 5.7).

         5.8 FINANCIAL STATEMENTS. The Company has furnished to the Purchasers
the most recent annual financial statements (the "Financial Statements"),
certified by the Chief Financial Officer or the Vice-President and Treasurer,
including balance sheets and related statements of income, retained earnings and
cash flow, as described on Schedule 5.8. Such Financial Statements (including
the notes thereto) present fairly the financial condition of the Company and its
Subsidiaries on a consolidated basis as of the end of such fiscal period and the
results of its operations and the changes in its financial position for the
fiscal period then ended, all in conformity with GAAP applied on a basis
consistent with that of the preceding fiscal period. Neither the Company nor its
Subsidiaries has incurred any obligation or liability (absolute, contingent,
liquidated or unliquidated) material to the Company and its Subsidiaries, taken
as a whole, except for (i) those reflected in the Financial Statements on
Schedule 5.8, (ii) those that have been incurred or have arisen in the ordinary
course of business since December 31, 1999, (iii) those disclosed in the
Company's filings with the Commission, (iv) those listed on schedules attached
to this Agreement and (v) those permitted or arising under this Agreement and
the other Transaction Documents. The Company and each of its Subsidiaries have
made and kept books, records and accounts which, in reasonable detail,
accurately and fairly reflect their respective transactions and dispositions of
their assets.

                                       17
<PAGE>

         5.9 DISCLOSURE. No representation or warranty made by the Company in
this Agreement is or was false or misleading as of the date made in any material
respect (including by omission of material information necessary to make such
representation, warranty or statement not misleading).

         5.10 COMPLIANCE WITH MATERIAL AGREEMENTS. As of the date hereof, except
as set forth on Schedule 5.10, neither the Company nor any of its Subsidiaries,
or to the Company's knowledge, any other party is in violation of any term of
any material Contractual Obligation to which it is a party or by which it or its
properties are bound that would reasonably be expected to have a Material
Adverse Effect. To the Company's knowledge, except as set forth on Schedule
5.10, no event has occurred or circumstance exists that (with or without notice
or the passage of time or both) would result in a default in a material respect
under a material Contractual Obligation or would give any party to a Contractual
Obligation the right to exercise any remedy under such Contractual Obligation or
to cancel, terminate or modify such Contractual Obligation which would
reasonably be expected to have a Material Adverse Effect. Except as set forth on
Schedule 5.10, neither the Company nor any Subsidiary has given notice to or
received notice from any other Person relating to an alleged, possible or
potential default under any material Contractual Obligation which would
reasonably be expected to have a Material Adverse Effect.

         5.11 LABOR MATTERS. As of the date hereof, (a) no strikes or other
material labor disputes against either the Company or its Subsidiaries are
pending or, to either the Company or its Subsidiaries' knowledge, threatened;
(b) hours worked by and payment made to employees of the Company or any of its
Subsidiaries comply with the Fair Labor Standards Act and each other federal,
state, local or foreign law applicable to such matter; (c) all payments due from
either the Company or its Subsidiaries for employee health and welfare insurance
have been paid or accrued as a liability on the books of such entity; (d)
neither the Company nor any of its Subsidiaries is a party to or bound by any
collective bargaining agreement, management agreement, consulting agreement or
any employment agreement (e) there is no organizing activity involving either
the Company or its Subsidiaries pending or, to either the Company or its
Subsidiaries' knowledge, threatened by any labor union or group of employees;
(f) there are no representation proceedings pending or, to any either the
Company or its Subsidiaries' knowledge, threatened with the National Labor
Relations Board, and no labor organization or group of employees of either the
Company or its Subsidiaries has made a pending demand for recognition; and (g)
except as set forth in Schedule 5.12, there are no complaints or charges against
either the Company or its Subsidiaries pending or, to the knowledge of the
executive officers of the Company, threatened to be filed with any Governmental
Authority or arbitrator based on, arising out of, in connection with, or
otherwise relating to the employment or termination of employment by either the
Company or its Subsidiaries of any individual which, if adversely determined,
would reasonably be expected to have a Material Adverse Effect.

         5.12     LITIGATION.
         (a) Except as set forth in Schedule 5.12, there is no pending action,
suit or, to the Company's knowledge, threatened proceeding by or before any
Governmental Authority against the Company or any of its Subsidiaries or
affecting any of its properties, rights or licenses which if adversely decided
would reasonably be expected to have a Material Adverse Effect. To the Company's
knowledge, no event has occurred or circumstance exists that may give rise to or
serve as a basis for any action, suit or proceeding to be brought or threatened
against the Company or any Subsidiary, in which an outcome adverse to the
Company or Subsidiary would reasonably be expected to have a Material Adverse
Effect. There is no pending or, to the Company's knowledge, threatened action,
suit or proceeding that challenges the transactions contemplated by the
Transaction Documents or that would have the effect of preventing, delaying,
making illegal or otherwise interfering with the transactions contemplated by
the Transaction Documents.

                                       18
<PAGE>

         (b) Neither the Company nor any Subsidiary is in violation of any
applicable Requirements of Law the consequences of the violation of which would
reasonably be expected to have a Material Adverse Effect. To the Company's
knowledge, no event has occurred or circumstance exists that (with or without
notice or the passage of time or both) would constitute or result in a violation
by the Company or any Subsidiary of any applicable Requirements of Law the
consequences of the violation of which would reasonably be expected to have a
Material Adverse Effect.

         5.13 RIGHTS TO PROPERTY. Each of the Company and its Subsidiaries has
good and marketable title, subject only to the encumbrances permitted under the
Senior Loan Agreement, to all personal property purported to be owned by it and
to all property reflected in the most recent balance sheet referred to in
Section 5.8 (except as sold or otherwise disposed of in the ordinary course of
business as no longer used or useful in the conduct of the business). Each lease
of real and personal property to which the Company or any of its Subsidiaries is
a party is in full force and effect and, except for such defaults as would not
have a Material Adverse Effect, is not subject to termination because of default
or otherwise. The Company and its Subsidiaries do not own nor have they entered
into any contract or commitment to acquire real property or any interest therein
other than such Leases.

         5.14 TAXES.
         (a) Except as set forth in Schedule 5.14, all Tax Returns required to
be filed by each of the Company and its Subsidiaries have been properly
prepared, executed and filed and were correct and complete in all material
respects, and all Taxes upon such entity or upon any of its respective
properties, incomes, sales or franchises which are shown to be due and payable
thereon have been paid, other than Taxes or assessments the validity or amount
of which such entity is contesting in good faith. The Tax reserves and
provisions for Taxes on the books of each of the Company and its Subsidiaries
are adequate for all open years and for its current fiscal period. Except as set
forth on Schedule 5.14, none of these Tax Returns is currently under audit or
examination, and neither the Company nor any Subsidiary has received notice from
any Governmental Authority that (i) any Tax Return that it filed will be audited
or examined or that (ii) it is or may be liable for additional Taxes in respect
of any Tax Return or for payment of Taxes in respect of a Tax Return that it did
not file (because, for example, it believed that it was not subject to taxation
by the jurisdiction in question).

         (b) Except as set forth on Schedule 5.14, the Company and its
Subsidiaries have withheld and paid to the proper Governmental Authorities all
Taxes that they were required to withhold and pay in respect of compensation or
other amounts paid to any employee or independent contractor.

                                       19
<PAGE>

         (c) Except as set forth on Schedule 5.14, neither the Company nor any
Subsidiary has extended the time in which to file any Tax Return, waived the
statute of limitations for any Tax or agreed to any extension of time for a Tax
assessment or deficiency.

         5.15 NO MATERIAL ADVERSE CHANGE. Since December 31, 1999, (i) there has
been no Material Adverse Change and (ii) except as set forth on Schedule 5.15
and the transactions contemplated by this Agreement and the other Transaction
Documents, the Company and its Subsidiaries have operated their business in the
ordinary course of business in all material respects.

         5.16 NO BROKERAGE FEES. Except as set forth on Schedule 5.16, no
brokerage or other fee, commission or compensation is to be paid by the Company
or any Subsidiary to any Person in connection with the transactions hereunder
except as contemplated herein.

         5.17 ERISA.
         (a) In the case of each Plan that the Company or any Subsidiary
maintains or contributes to (or ever maintained or contributed to): (i) the Plan
(and each related trust or insurance policy) complies (or complied) in form and
in operation in all material respects with the applicable requirements of ERISA
and the Code, as the case may be; (ii) all required contributions to or premiums
or other payments in respect of the Plan have been paid, and all required
reports and descriptions have been filed with the proper Governmental Authority
or distributed to participants as appropriate; (iii) there have been no
"prohibited transactions' (as defined in Section 406 of ERISA and Section 4975
of the Code) in respect of the Plan; (iv) no action, suit, proceeding,
arbitration, hearing or investigation in respect of the administration of the
Plan or the investment of Plan assets is pending or, to the Company's knowledge,
threatened, and to the Company's knowledge, there is no basis for any such
action, suit, proceeding, arbitration, hearing or investigation; and (v) no Plan
is subject to Title IV of ERISA.

         (b) Except to the extent required by Section 4980B of the Code, neither
the Company nor any Subsidiary provides health or other welfare benefits to any
retired or former employee or is obligated to provide health or other welfare
benefits to any active employee following his or her retirement or other
termination of service.

         5.18 INTELLECTUAL PROPERTY. Each of the Company and its Subsidiaries
owns or possesses the right to use all patents, trademarks, service marks, trade
names, copyrights, know-how, franchises, software and software licenses used in
or necessary for the operation of its business as currently conducted, free from
burdensome restrictions except where such failure to own or possess the right to
use would not reasonably be expected to have a Material Adverse Effect. All such
rights are described on Schedule 5.18. Each executive officer and senior manager
of the Company and its Subsidiaries has executed and delivered to the Company a
confidentiality agreement. To the Company's knowledge, no present or former
executive officer or senior manager has breached any such agreement.

                                       20
<PAGE>

         5.19 ENVIRONMENTAL. Each of the Company and its Subsidiaries is in
compliance with all Environmental Laws applicable to such entity or its business
except for such non-compliances as in the aggregate would not reasonably be
expected to have a Material Adverse Effect. Neither the Company nor any of its
Subsidiaries has received notice of, or is aware of, any violation or alleged
violation, or any liability or asserted liability, under any Environmental Law,
with respect to such entity or its business or its premises. The only premises
occupied by the Company and its Subsidiaries are office spaces in multi-tenant
commercial office buildings.

         5.20 SUBSIDIARIES. Neither the Company nor its Subsidiaries has any
Subsidiaries, other than the Subsidiaries listed on Schedule 5.20 and all such
Subsidiaries are wholly-owned, directly or indirectly, by the Company.

         5.21 TRANSACTIONS WITH AFFILIATES. No Affiliate and no officer or
director of either the Company or any of its Subsidiaries or any individual
related by blood, marriage, adoption or otherwise to any such Affiliate, officer
or director, or any Person in which any such Affiliate, officer, director or
individual related thereto owns any material beneficial interest, is a party to
any agreement, contract, commitment or transaction with the Company or any of
its Affiliates or has any material interest in any material property used by the
Company or any of its Affiliates, except as set forth on Schedule 5.21.

         5.22 CAPITALIZATION. As of the Closing Date, the authorized capital
stock of the Company and its Subsidiaries and the issued and outstanding shares
thereof are as described on Schedule 5.22. As of the Closing Date, all
outstanding shares of capital stock of the Company and its Subsidiaries will be
duly authorized and validly issued, fully paid, nonassessable and free and clear
of any Lien created by the Company or any Subsidiary thereof (other than Liens
under the Senior Loan Documents). Except as described in Schedule 5.22, no other
class of capital stock or other ownership interests of the Company or its
Subsidiaries are authorized or outstanding. Except as described in Schedule
5.22, neither the Company nor any Subsidiary is subject to any obligation
(contingent or otherwise) to repurchase, redeem or otherwise acquire its capital
stock or any warrants, options or other rights to acquire its capital stock. The
Company does not have any outstanding securities convertible into capital stock
of the Company (other than the Class B Common Stock and, as of the Closing, the
Preferred Stock); and except for shares of Common Stock reserved for issuance
upon the exercise of outstanding warrants or in connection with the Company
Stock Option Plan, the Company does not have any shares of capital stock
reserved for issuance (other than shares of Common Stock reserved for issuance
upon conversion of the Class B Common Stock and, as of the Closing, upon
conversion of the Preferred Stock). Except as set forth on Schedule 5.22 and
other than the Company's outstanding warrants and stock options and this
Agreement, the Company does not have any commitment to authorize, issue or sell
any of its capital stock or securities convertible into or exchangeable for any
of its capital stock. Neither the Company nor any of its Subsidiaries is a party
to any "phantom stock", employee stock option plan, other equity-based incentive
plan or similar agreement, other than the Company Stock Option Plan. Schedule
5.22 sets forth the number of shares of capital stock reserved for issuance upon
the exercise of options granted or available to be granted under the Company
Stock Option Plan. Schedule 5.22 also lists all of the Company's outstanding
warrants to purchase capital stock. Except as set forth on Schedule 5.22, there
are no preemptive or similar rights to purchase or otherwise acquire equity
securities of, or interests in, the Company or any of its Subsidiaries pursuant
to any Requirements of Law or Contractual Obligations applicable to the Company
or any of its Subsidiaries. There are no existing rights with respect to
registration or sale or resale under the Securities Act or the securities or
blue sky laws of any state or jurisdiction of any securities of the Company or
any of its Subsidiaries. The shares of Preferred Stock to be issued to each
Purchaser on the Closing Date, and any additional shares of Preferred Stock to
be issued as preferential dividends pursuant to the terms thereof will, upon
issuance to such Purchaser, have the designations, preferences, qualifications,
limitations, restrictions and such special and relevant rights as are set forth
in the Certificate of Designation and the DGCL.

                                       21
<PAGE>

         5.23 COMMISSION FILINGS. Since April 23, 1998 (the date of the
Company's initial public offering), the Company has filed with the Commission,
on a timely basis, all registration statements, reports on Form 10-K, 10-Q and
8-K, proxy statements and information statements, and other documents that it
was required to file under the Securities Act or the Exchange Act. As of the
respective dates of such filings, none of the Company's filings with the
Commission contained (and the Company's most recent Form 10-K does not contain)
an untrue statement of a material fact or omitted (and the Company's most recent
Form 10-K does not omit) to state any material fact necessary to make any
statement of a material fact that it contained, in light of the circumstances in
which made, not misleading; and when filed with the Commission, each of such
filings with the Commission complied in all material respects with the
applicable requirements of the Securities Act or Exchange Act, as applicable.
The Company is eligible to file a registration statement on Form S-3 and has
taken all actions which would be required to permit sales of its securities
under Rule 144 under the Securities Act.

         5.24 INVESTMENT COMPANY; PUBLIC UTILITY HOLDING COMPANY. Neither the
Company nor any of its Subsidiaries is an "investment company" or a "company
controlled by an investment company" or an "affiliated person" or "promoter" or
"principal underwriter" for, an "investment company," within the meaning of the
Investment Company Act of 1940, as amended, or a "holding company," or a
"subsidiary company" of a "holding company," or an "affiliate" of a "holding
company" or of a "subsidiary company" of a "holding company," within the meaning
of the Public Utility Holding Company Act of 1935, as amended.

         5.25 SECURITIES ACT. Based upon the representations and warranties of
each Purchaser in Section 6 of this Agreement, (i) the Preferred Stock to be
issued pursuant to the terms of this Agreement, any Preferred Stock to be issued
as preferential dividends pursuant to the terms thereof and the Common Stock
issuable upon conversion of such Preferred Stock and (ii) the issuance by the
Company thereof, are not required to be registered under the Securities Act or
under the securities or blue sky laws of any state or jurisdiction.

                                       22
<PAGE>

         5.26 BOOKS AND RECORDS. The minute books of the Company and of each of
the Subsidiaries contain, in all material respects, true, complete and accurate
records of all meetings and other corporate actions of each of their respective
stockholders, partners, members, board of directors and all committees, if any,
appointed by its board of directors in each case, since the later of (x) the
formation of the Company or such Subsidiary or (y) the date of the Company's
initial public offering, and accurate and complete copies thereof have been made
available to the Purchasers.

         5.27 CERTAIN PAYMENTS. Other than discounts, rebates and incentives
provided to customers and commissions and similar compensation paid to sales
agents in the ordinary course of business, neither the Company nor any
Subsidiary nor any officer, director, employee or agent of the Company or any
Subsidiary or, to the Company's knowledge, any other Person associated with or
acting for or on behalf of the Company or any Subsidiary, has directly or
indirectly made or paid any contribution, gift, bribe, rebate, payoff, kickback
or other payment (whether in money, property or services or any other form) to
any Person (i) in order to gain or pay for favorable treatment in obtaining
business or special concessions or (ii) in violation of any Requirements of Law
(including Section 30A of the Exchange Act).

         5.28 YEAR 2000 COMPLIANCE. The computer systems and switches of the
Company (including all software, hardware, workstations and related components,
automated devices, embedded chips and other date sensitive equipment) are Year
2000 Compliant except where the failure to be Year 2000 Compliant would not have
a Material Adverse Effect.

         5.29 TRADE RELATIONS. Except as set forth on Schedule 5.29, there
exists no actual or, to the knowledge of the Company, threatened termination,
cancellation or limitation of, or any modification or change in, the business
relationship between the Company or any of its Subsidiaries and any customer or
supplier that would reasonably be expected to have a Material Adverse Effect or
to prevent the Company or any of its Subsidiaries from conducting their business
after the consummation of the transactions contemplated by this Agreement in
substantially the same manner as it is currently being conducted or is proposed
to be conducted.

                                   ARTICLE VI

                REPRESENTATIONS AND WARRANTIES OF THE PURCHASERS

         Each Purchaser as to itself and not as to any other Purchaser hereby
severally represents and warrants to the Company, as appropriate, as follows:

         6.1 AUTHORIZATION; NO CONTRAVENTION. Such Purchaser (unless an
individual) is duly organized, validly existing and in good standing as a
corporation, limited liability company or general or limited partnership under
the laws of the state of its incorporation or formation. The execution, delivery
and performance by such Purchaser of this Agreement (a) is within the such
Purchaser's power and authority and has been duly authorized by all necessary
partnership, company or corporate action, (b) does not contravene the terms of
such Purchaser's organizational documents or any amendment thereof and (c) will
not violate, conflict with or result in any breach or contravention of any
material Contractual Obligation of such Purchaser, or any material Requirement
of Law directly relating to such Purchaser.

                                       23
<PAGE>

         6.2 BINDING EFFECT. This Agreement has been duly executed and delivered
by such Purchaser, and this Agreement constitutes the legal, valid and binding
obligation of such Purchaser enforceable against it in accordance with its
terms, except as enforceability may be limited by applicable bankruptcy,
insolvency, reorganization, moratorium, fraudulent conveyance or other similar
laws affecting the enforcement of creditors' rights generally or by general
equitable principles relating to enforceability.

         6.3 ACCREDITED INVESTOR; PURCHASE FOR OWN ACCOUNT. Such Purchaser is an
"accredited investor" within the meaning of Regulation D under the Securities
Act. The Preferred Stock to be issued pursuant to the terms of this Agreement,
any Preferred Stock to be issued as preferential dividends pursuant to the terms
thereof and the shares of Common Stock to be issued upon conversion of such
Preferred Stock are being or will be acquired for its own account and with no
intention of distributing or reselling such securities or any part thereof in
any transaction that would be in violation of the Securities Act or the
securities laws of any state, without prejudice, however, to the rights of such
Purchaser at all times to sell or otherwise dispose of all or any part of such
Preferred Stock or any shares of Common Stock under an effective registration
statement under the Securities Act, or under an exemption from such registration
available under the Securities Act. If such Purchaser should in the future
decide to dispose of such Preferred Stock or any shares of Common Stock issued
upon conversion of the Preferred Stock, such Purchaser understands and agrees
that it may do so only in compliance with the Securities Act and applicable
state securities laws, as then in effect. Such Purchaser agrees to the
imprinting, so long as required by law, of a legend on certificates representing
such Preferred Stock or any shares of Common Stock issued upon conversion of the
Preferred Stock to the following effect:

         "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
         REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE
         SECURITIES LAWS OF ANY STATE AND MAY NOT BE SOLD OR OTHERWISE DISPOSED
         OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH
         ACT AND APPLICABLE STATE SECURITIES LAWS OR PURSUANT TO AN APPLICABLE
         EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND SUCH
         LAWS."

         The requirement to include the legend set forth above shall cease and
terminate as to any particular shares of Preferred Stock or Common Stock (a)
when, in the opinion of Ropes & Gray, or other counsel reasonably acceptable to
the Company, such legend is no longer required in order to assure compliance by
the Company with the Securities Act or (b) when such shares have been
effectively registered under the Securities Act or transferred pursuant to Rule
144. Whenever (x) such requirement shall cease and terminate as to any such
shares or (y) such shares shall be transferable under paragraph (k) of Rule 144,
the holder thereof shall be entitled to receive from the Company, without
expense, new certificates not bearing the legend set forth above.

                                       24
<PAGE>

         Such Purchaser also agrees to the imprinting, so long as required by
law, of a legend on certificates representing its shares of Preferred Stock:

         "THESE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE TERMS
         AND CONDITIONS, INCLUDING CERTAIN TRANSFER RESTRICTIONS, OF THAT
         CERTAIN CORPORATE GOVERNANCE AGREEMENT, DATED AS OF APRIL 11, 2000,
         AMONG THE COMPANY AND CERTAIN OF THE COMPANY'S STOCKHOLDERS. A COPY OF
         SUCH AGREEMENT MAY BE OBTAINED AT NO COST BY WRITTEN REQUEST TO THE
         COMPANY MADE BY THE HOLDER OF THIS CERTIFICATE."

         6.4 GOVERNMENTAL AUTHORIZATIONS. Except for clearance under the
Hart-Scott-Rodino Act, no notice to, consent of, or registration, filing or
declaration with, any Governmental Authority is required in connection with such
Purchaser's execution, delivery and performance of this Agreement and the
Transaction Documents and consummation of the contemplated transactions.

         6.5 NO BROKERS OR FINDERS. Except as disclosed on Schedule 6.5, no
agent, broker, finder, or investment or commercial banker or other Person or
firm engaged by or acting on behalf of such Purchaser in connection with the
negotiation, execution or performance of this Agreement or the transactions
contemplated herein is or will be entitled to any brokerage or finder's or
similar fee or other commission as a result of this Agreement or such
transaction.

         6.6 OWNERSHIP OF COMPANY SECURITIES; VOTING AND OTHER AGREEMENTS.
Immediately following the Closing, such Purchaser will not beneficially own any
securities of the Company other than the Preferred Stock and the Option
Preferred Stock issuable upon the exercise of the Option Agreement. Such
Purchaser does not have any agreements, arrangements or understandings with any
other Person (other than with other Purchasers who are Affiliates of such
Purchaser) with regard to acquiring, holding, voting or disposing of the
securities of the Company other than as set forth in this Agreement and in the
other Transaction Documents to which such Purchaser is a party.

                                   ARTICLE VII

                                    COVENANTS

         7.1 HSR CLEARANCE. The Company and each of the Purchasers shall
cooperate with and provide each other, respectively, with any information that
each party reasonably requires and file such notices and responses as may be
necessary to enable each party to obtain any required clearance under the
Hart-Scott-Rodino Act. Each such Purchaser required to obtain such clearance
agrees to use all reasonable best efforts to obtain such clearance as promptly
as practicable on or prior to the Closing Date.

                                       25
<PAGE>

         7.2 RESERVATION OF SHARES. The Company shall at all times reserve and
keep available out of the aggregate of its authorized but unissued shares, free
of preemptive rights, (i) such number of its duly authorized shares of Preferred
Stock as shall be sufficient to enable the Company to pay preferential dividends
pursuant to the terms of the Certificate of Designation with respect to all
shares of Preferred Stock issued thereunder, (ii) such number of duly authorized
shares of Option Preferred Stock as shall be sufficient to enable the Company to
issue the full number of shares of Option Preferred Stock issuable upon exercise
of the Option, (iii) such number of its duly authorized shares of Option
Preferred Stock as shall be sufficient to enable the Company to pay preferential
dividends pursuant to the terms of the Option Stock Designation with respect to
all shares of Option Preferred Stock issued thereunder and (iv) such number of
its duly authorized shares of Common Stock as shall be sufficient to enable the
Company to issue Common Stock upon conversion of all such Preferred Stock and
Option Preferred Stock.

         7.3 PUC CONSENTS. The Company shall use all of its commercially
reasonable efforts to obtain all of the authorizations, consents, approvals,
licenses and/or exemptions listed on Schedule 5.4 on or prior to the Closing
Date.

         7.4 DELIVERY OF FINANCIAL AND BUSINESS INFORMATION. The Company shall
deliver the following to (i) each Purchaser and (ii) each Permitted Transferee
(holding at least 5% of the Underlying Common Stock), so long as at least 20% of
the Underlying Common Stock continues to be beneficially owned by the Purchasers
and Permitted Transferees:

         (a) promptly upon becoming available, one copy of (i) each financial
statement, report, notice or proxy statement sent by the Company or any
Subsidiary to public securities holders generally, and (ii) each regular or
periodic report, each registration statement that has become effective (without
exhibits unless expressly requested), and each final prospectus and all related
amendments filed by the Company or any Subsidiary with the Commission;

         (b) promptly, and in any event within 10 days after the Company becomes
aware of the existence of any default under a material Contractual Obligation, a
written notice specifying the nature and period of duration of the default and
the action that the Company is taking or proposes to take with respect to the
default;

         (c) concurrently with the delivery of such information to the lenders
under the Senior Loan Agreement, copies of annual and quarterly financial
statements of the Company prepared in accordance with GAAP; and

         (d) promptly upon becoming available for each month, the Company's (i)
condensed consolidated financial statements, including income statement, balance
sheet and statement of cash flow, (ii) revenue analysis, (iii) summary of
customer activity, including customers, ISP trunk, voice trunk and voice lines,
(iv) functional organizational chart and staffing analysis, (v) summary of
network cost package, (vi) selling, general and administrative expense analysis,
(vii) capital spending summary, and (viii) summary income statements through
EBITDA by major markets.

                                       26
<PAGE>

         7.5 ACCESS TO PROPERTIES. The Company shall permit representatives
designated by (i) the Purchasers and (ii) Permitted Transferees holding at least
5% of the Underlying Common Stock (both prior to Closing and for as long as the
Purchasers and their Permitted Transferees own at least 20% of the Underlying
Common Stock), upon reasonable notice, during normal business hours and at such
other times as such Purchasers or Permitted Transferees reasonably may request,
and without unreasonable interference with the Company's operations, to visit
and inspect, at their expense, any of the properties, offices, personnel,
accountants and advisors of the Company and its Subsidiaries with respect to any
of the businesses and assets of the Company and its Subsidiaries, and the
transactions contemplated by the Transaction Documents, and to examine the
corporate and financial records of the Company and its Subsidiaries.

         7.6 PRE-CLOSING COVENANTS. At all times after execution of this
Agreement and prior to the Closing (unless and until this Agreement is
terminated in accordance with its terms), the Company shall not, without the
prior written consent of the Purchasers (except as otherwise expressly permitted
or required by this Agreement or any of the Transaction Documents), directly or
indirectly take or commit to take any action that (i) would constitute a
violation of the restrictions in Section 3.2 of the Corporate Governance
Agreement if the action in question were to be taken after the Closing or that
(ii) would cause an adjustment to the Conversion Price under Sections 4.3, 4.4
or 4.5 of the Certificate of Designation if the Certificate of Designation had
been duly filed and in effect as of the date of this Agreement.

         7.7 EXCLUSIVITY.

         (a) Except for the possible issuance and sale of up to 25,000 shares of
the Company's Series C Convertible Preferred Stock to some of the lenders under
the Senior Loan Agreement, the Company shall not, and shall cause its
Affiliates, employees, investment bankers, attorneys, accountants and other
agents not to, initiate, solicit or encourage any inquiries relating to, or the
making of any Other Proposal or engage in negotiations or discussions with, or
furnish any information to, any third party relating to any Other Proposal. As
used in this Section 7.8, "Other Proposal" means any proposal made by any
Person, other than the Purchasers, as a group, to acquire from the Company or
any of its Affiliates, any convertible preferred stock, any other capital stock
or any securities having equity or profit participation features ("Equity
Securities"), or any debt securities in lieu of, or substitution for, any Equity
Securities; provided, that the term "Other Proposal" shall not include (i) any
proposed acquisition, by sale, merger or otherwise, of all or substantially all
of the Company's outstanding capital stock or assets or (ii) any proposed stock
or asset acquisitions, by sale, merger or otherwise, by the Company or one of
its Affiliates which involves the issuance to the sellers by the Company of its
capital stock as consideration.

         The Company shall advise the Purchasers in writing of (i) the receipt,
directly or indirectly, of any inquiries relating to an Other Proposal promptly
following such receipt and (ii) the status of any discussions or negotiations
with respect thereto. Following the receipt, directly or indirectly of any Other
Proposal (or any inquiry referred to in clause (i) above), the Company shall
furnish to the Purchasers either a copy of such Other Proposal (or such inquiry)
or a written summary of such Other Proposal (or such inquiry). In addition, the
Company shall not, and shall cause its Affiliates, employees, investment
bankers, attorneys, accountants and other agents not to, actually consummate, or
enter into any Contractual Obligation or otherwise commit to consummate, any
transaction that includes or would include as any part thereof the acquisition
by any Person, other than the Purchasers, directly or indirectly, from the
Company or any of its Affiliates, any Equity Securities, or any debt securities
in lieu of or substitution for any Equity Securities.

                                       27
<PAGE>

         (b) The restrictions on and obligations of the Company under Section
7.8(a) shall terminate on the earlier to occur of (i) the Closing Date or (ii)
the termination of this Agreement pursuant to Section 8.3(a).

         7.8 TAX MATTERS. The Purchasers intend that no pay-in-kind dividends on
the Preferred Stock or Option Preferred Stock will, when paid or accrued, be
includible in the Purchasers' gross income for federal, state or local tax
purposes. Accordingly, unless the Company concludes in good faith, with the
assistance and advice of its accountants and counsel, that there is no
reasonable basis to make or file any Tax Return that is consistent with such
intention, the Company shall not make or file any Tax Return that is
inconsistent with such intention.

         7.9 CONFIDENTIALITY. Each Purchaser will hold, and will use its
reasonable efforts to cause its Permitted Transferees, and each Purchaser's and
each Permitted Transferee's officers, partners, directors, employees,
accountants, counsel, consultants, advisors and agents (the "Representatives")
to hold, in confidence, at all times unless compelled to disclose by judicial or
administrative process or by other Requirements of Law, all confidential
documents and information concerning the Company and it Affiliates that are
furnished to such Purchaser and its Permitted Transferees, except to the extent
that such information can be shown to have been (i) previously known on a
nonconfidential basis by such Purchaser, Permitted Transferee or such
Representatives or (ii) in the public domain through no fault of such Purchaser,
such Permitted Transferee or such Representative. If any Purchaser or Permitted
Transferee, or any of their respective Representatives is requested to disclose
any confidential information by judicial or administrative process or by other
Requirements of Law, such Person shall promptly notify the Company of such
request so that the Company may seek an appropriate protective order. Each
Purchaser agrees that it will not, and will use its reasonable best efforts to
cause its Permitted Transferees and the Representatives not to, use any
confidential documents or information for any purpose other than monitoring and
evaluating its investment in the Company and in connection with the transactions
contemplated by this Agreement. If this Agreement is terminated, each Purchaser
will, and will use its reasonable best efforts to cause its Representatives to,
destroy or deliver to the Company all documents and other materials, and all
copies thereof, obtained by such Purchaser, or on its behalf, from the Company
in connection with this Agreement and an investment in the Company.

                                       28
<PAGE>

         7.10 SCHEDULE 13D AND 13G. Each Purchaser agrees to provide the Company
with a copy of any Schedule 13D or 13G that it intends to file at any time with
the Commission in connection with their purchase of Preferred Stock in advance
of such filing.

         7.11 ELECTION OF DIRECTORS. The Company will cause two representatives
of the Purchasers to be elected to the Company's Board of Directors on the day
immediately following the Closing Date.

         7.12 SERIES C DESIGNATION. Without the prior written consent of the
Required Holders, the Company agrees that (a) it will not sell more than an
aggregate of 25,000 shares of Series C Preferred Stock and no such sale shall
occur on or after April 17, 2000, (b) such stock will not be sold for a purchase
price of less than $1,000 per share, (c) such stock will not be sold to any
Person other than the current lenders under the Senior Loan Agreement or their
Affiliates, no one of which will be permitted to purchase more than 10,000
shares of such stock, (d) the Series C Preferred Stock Purchase Agreement will
not be amended, supplemented or otherwise modified in any material respect prior
to the closing thereunder, except to include therein the number of shares of
Series C Preferred Stock to be purchased thereunder and (e) the Series C
Designation will not be amended, supplemented or otherwise modified prior to the
filing of such designation with the Secretary of State of Delaware, except to
include therein the number of shares of Series C Preferred Stock to be created
thereunder.

         7.13 ADDITIONAL COVENANT. The parties hereto agree to Exhibit M which
is incorporated herein by this reference.

                                  ARTICLE VIII

                          INDEMNIFICATION; TERMINATION

         8.1 INDEMNIFICATION. Effective upon the Closing, the Company agrees to
indemnify and hold harmless the Purchasers and their Affiliates and their
officers, directors, agents, employees, subsidiaries, partners and controlling
Persons (each, a "Company Indemnified Party") to the fullest extent permitted by
law, from and against any and all losses, demands, actions, costs, claims,
damages, expenses (including reasonable fees, disbursements and other charges of
counsel) or other liabilities (collectively, "Company Liabilities") incurred or
suffered by such Company Indemnified Party resulting from or arising out of (i)
any misrepresentation or breach of any representation or warranty of the Company
in this Agreement, any other Transaction Document or any certificate or
instrument delivered pursuant thereto, (ii) any breach of any covenant or
obligation of the Company in this Agreement or any other Transaction Document,
or (iii) any investigation or proceeding against the Company or any Company
Indemnified Party and arising out of or in connection with this Agreement or any
of the Transaction Documents, whether or not the transactions contemplated by
this Agreement are consummated, which investigation or proceeding requires the
participation of, or is commenced or filed against, any Company Indemnified
Party because of this Agreement, any other Transaction Document or such other
documents or transactions contemplated hereby or thereby; provided that (x) the
Company shall not be liable under Section 8.1(iii) to a Company Indemnified
Party for any liabilities resulting primarily from any actions that involved the
gross negligence or willful misconduct of such Company Indemnified Party or the
breach by any Company Indemnified Party of any representation, warranty,
covenant or other agreement of such Indemnified Party contained herein or in any
other Transaction Documents.

                                       29
<PAGE>

         8.2 NOTIFICATION. The Company Indemnified Party, under Section 8.1(iii)
will, promptly after the receipt of notice of the commencement of any action,
investigation, claim or other proceeding against such Company Indemnified Party
in respect of which indemnity may be sought from the Company under Section
8.1(iii), notify the Company in writing of the commencement thereof. The
omission of any Company Indemnified Party so to notify the Company of any such
action shall not relieve the Company from any liability which it may have to
such Company Indemnified Party under Section 8.1(iii) unless, and only to the
extent that, such omission results in the Company's forfeiture of substantive
rights or defenses or the Company is otherwise irrevocably prejudiced in
defending such proceeding. In case any such action, claim or other proceeding
shall be brought against any Company Indemnified Party and it shall notify the
Company of the commencement thereof, the Company shall be entitled to assume the
defense thereof at its own expense, with counsel satisfactory to the Company
Indemnified Party; provided, that any Company Indemnified Party may, at its own
expense, retain separate counsel to participate in such defense. Notwithstanding
the foregoing, in any action, claim or proceeding in which both the Company, on
the one hand, and a Company Indemnified Party, on the other hand, is, or is
reasonably likely to become, a party, such Company Indemnified Party shall have
the right to employ separate counsel at the Company's expense and to control its
own defense of such action, claim or proceeding if, (a) the Company has failed
to assume the defense and employ counsel as provided herein, (b) the Company has
agreed in writing to pay such fees and expenses of separate counsel or (c) in
the reasonable opinion of counsel to such Company Indemnified Party, a conflict
or likely conflict exists between the Company, on the one hand, and such Company
Indemnified Party, on the other hand, that would make such separate
representation advisable, provided, however, that the Company shall not in any
event be required to pay the fees and expenses of more than one separate counsel
(and if deemed necessary by such separate counsel, appropriate local counsel who
shall report to such separate counsel). The Company agrees that it will not,
without the prior written consent of a Company Indemnified Party, settle,
compromise or consent to the entry of any judgment in any pending or threatened
claim, action or proceeding relating to the matters contemplated hereby (if such
Company Indemnified Party is a party thereto or has been actually threatened to
be made a party thereto) unless such settlement, compromise or consent includes
an unconditional release of such Company Indemnified Party from all liability
arising or that may arise out of such claim, action or proceeding. The Company
shall not be liable for any settlement of any claim, action or proceeding
effected against a Company Indemnified Party without the prior written consent
of the Company.

         8.3 TERMINATION.

         (a) This Agreement may be terminated at any time prior to the Closing
Date: (i) by mutual written agreement of the Company and each Purchaser; (ii) by
the Company or the Purchasers if the Closing shall not have been consummated on
or before June 30, 2000, (iii) by the Company or the Purchasers if a
Governmental Authority shall have issued a nonappealable final order, decree or
ruling or taken any action having the effect of permanently restraining or
enjoining the transactions contemplated by this Agreement or (iv) by the Company
if any one of the Purchasers (who is obligated to purchase at least 100,000
shares of the Preferred Stock) defaults in its obligations under this Agreement
to purchase such Preferred Stock (a "Closing Failure").

                                       30
<PAGE>

         (b) If this Agreement is terminated as permitted by Section 8.3(a),
such termination shall be without liability of any party hereto (or their
respective Affiliates) to any other party hereto; provided, however, that
nothing shall relieve any party from liability if such termination shall result
from the (i) willful failure by any party to fulfill a condition to the
performance of the obligations of the other parties, (ii) willful failure by any
party to perform a covenant of this Agreement, (iii) willful breach by any party
hereto of any representation or warranty contained in this Agreement or (iv) a
Closing Failure. The provisions of Sections 7.10, 8.3, 9.2, 9.8 and 9.11 shall
survive any termination hereof pursuant to Section 8.3.

                                   ARTICLE IX

                                  MISCELLANEOUS

         9.1 CLAIMS AND SUITS UNDER SECTION 8.1. No claim may be made or suit
instituted under Section 8.1 with respect to any breach of a representation or
warranty (except if it relates to a breach of Sections 5.1, 5.2, 5.3, 5.8, and
5.22 or if it relates to fraud) after the date that is eighteen (18) months
after the Closing Date or, as to the representations and warranties in Section
5.14 after the expiration of applicable statutes of limitation with respect to
the subject matter of each such representation and warranty, unless the Company
Indemnified Party has given the indemnifying party written notice of such claim
or suit (describing with reasonable specificity the amount of and basis for such
claim or suit) on or prior to such date.

         9.2 NOTICES. All notices, requests, claims, demands and other
communications ("Notices") provided for or permitted hereunder shall be made in
writing and shall be by registered or certified first class mail, return receipt
requested, telecopier, recognized overnight courier service or personal
delivery:

         (a)      if to the Company:

                           US LEC Corp.
                           Transamerica Square
                           401 N. Tryon Street, Suite 1000
                           Charlotte, North Carolina 28202
                           Attention:  General Counsel
                           Telecopier:  (704) 319-3098

                                       31
<PAGE>

         with a required copy to:

                           Moore & Van Allen, PLLC
                           100 North Tryon Street, Floor 47
                           Charlotte, North Carolina 28202-4003
                           Attention:  Barney Stewart III
                           Telecopier:  (704) 331-1151

         (b)      if to the Purchasers:

                           Bain Capital, Inc.
                           Two Copley Place
                           Boston, Massachusetts 02116
                           Attention:  Ian K. Loring
                           Telecopier:  (617) 572-3274

                           and to:

                           Thomas H. Lee Partners, L.P.
                           75 State Street, 26th Floor
                           Boston, Massachusetts 02109
                           Attention:  Anthony J. DiNovi
                           Telecopier (617) 227-3514

         with a required copy to:

                           Ropes & Gray
                           One International Plaza
                           Boston, Massachusetts 02110-2624
                           Attention:  Philip J. Smith
                           Telecopier:  (617) 951-7050

         All Notices shall be deemed to have been duly given: when delivered by
hand, if personally delivered; when delivered by courier, if delivered by
commercial overnight courier service; five Business Days after being deposited
in the mail, postage prepaid, if mailed; and when receipt is acknowledged by the
individual to whom the telecopy is sent, if telecopied.

                                       32
<PAGE>

         9.3 SUCCESSORS AND ASSIGNS. This Agreement shall inure to the benefit
of and be binding upon the successors and permitted assigns of the parties
hereto. Subject to applicable securities laws and except as otherwise set forth
in the Transaction Documents (including, without limitation, the Corporate
Governance Agreement), the Purchasers may assign any of their rights under this
Agreement, to any Person who is a Permitted Transferee. The Company may not
assign any of its rights under this Agreement without the prior written consent
of the Purchasers. Except as provided in Article 9, no Person other than the
parties hereto and their successors and permitted assigns is intended to be a
beneficiary of any of the Transaction Documents.

         9.4 DETERMINATIONS, REQUESTS OR CONSENTS. Any amendment, supplement or
modification of or to any provision of this Agreement, any waiver of any
provision of this Agreement, and any consent to any departure of the Company
from the terms of any provision of this Agreement, shall be effective (a) only
if it is made or given in writing and signed by the Company and the Required
Holders (as defined below) in accordance with this Section 9.4, and (b) only in
the specific instance and for the specific purpose for which made or given. All
determinations, requests, consents, waivers or amendments to be made by the
Purchasers in their opinion or judgment or with their approval or otherwise
pursuant to this Agreement shall be made (i) at any time following the Closing,
by the holders of at least 51% of the then outstanding Purchaser Preferred Stock
or (ii) at any time prior to the Closing, by Purchasers who have committed to
purchase hereunder at least 51% of the Purchaser Preferred Stock (in either
case, the "Required Holders").

         9.5 COUNTERPARTS. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

         9.6 HEADINGS. The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

         9.7 GOVERNING LAW. This agreement shall be governed by and construed in
accordance with the laws of the State of Delaware without regard to the
principles of conflicts of law of such state.

         9.8 SEVERABILITY. If any one or more of the provisions contained
herein, or the application thereof in any circumstance, is held invalid, illegal
or unenforceable in any respect for any reason, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions hereof shall not be in any way impaired, unless the provisions held
invalid, illegal or unenforceable shall substantially impair the benefits of the
remaining provisions hereof.

                                       33
<PAGE>

         9.9 RULES OF CONSTRUCTION. Unless the context otherwise requires, "or"
is not exclusive, and references to sections or subsections refer to sections or
subsections of this Agreement. All pronouns and any variations thereof refer to
the masculine, feminine or neuter, singular or plural, as the context may
require.

         9.10 ENTIRE AGREEMENT. This Agreement, together with the exhibits and
schedules hereto and the other Transaction Documents, is intended by the parties
as a final expression of their agreement and intended to be a complete and
exclusive statement of the agreement and understanding of the parties hereto in
respect of the subject matter contained herein and therein. There are no
restrictions, promises, warranties or undertakings, other than those set forth
or referred to herein or therein. This Agreement, together with the exhibits
hereto, and the other Transaction Documents supersede all prior contemporaneous
agreements and understandings between the parties with respect to such subject
matter.

         9.11     CERTAIN EXPENSES.

         (a) The Purchasers and the Company shall each pay their own fees and
expenses in connection with the negotiation and preparation of this Agreement
and consummation of the transactions contemplated herein with the exception that
the Company shall pay or reimburse the Purchasers for their fees and expenses
(including HSR filing fees, the fees and expenses of their counsel and
accountants, and the expenses incurred by representatives of the Purchasers) for
the negotiation and preparation of the Transaction Documents and the
consummation of the purchase transactions contemplated thereby, including the
exercise of the Option Agreement. Thereafter, subject to the provisions of
Section 9.11(c), the Company shall reimburse the Purchasers for the reasonable
fees and expenses which they incur from time to time in consulting with their
counsel and accountants with respect to the Transaction Documents and any
amendments, supplements, consents or waivers with respect to such documents.
Reasonable documentation shall be provided to the Company by the Purchasers for
all fees and expenses which the Company has agreed to reimburse pursuant to this
Section 9.11(a).

         (b) The Company shall not be required to pay or reimburse the
Purchasers for any of their fees and expenses in the event that the Closing does
not occur; provided, however, the Company shall be required to pay or reimburse
the Purchasers for such fees and expenses if the Closing does not occur due to
the failure of the Company to satisfy the closing conditions under Section 3 of
this Agreement.

         (c) If any action, suit or proceeding is commenced by any Purchaser
after the Closing arising out of or related to an alleged breach by the Company
of a covenant in any Transaction Document, such Purchaser or Purchasers shall be
entitled to reimbursement by the Company of the attorneys fees and expenses,
accountants fees and expenses and other costs incurred in investigating,
prosecuting or defending such action, suit or proceeding, payable within 10 days
after presentation to the Company of reasonable documentation for such fees,
expenses and costs; provided, however, that the Company shall not be liable for
such fees and expenses in the event that it is finally determined that no such
breach occurred.

                                       34
<PAGE>

         9.12 PUBLICITY. Except as may be required by applicable law, none of
the parties hereto shall issue a publicity release or announcement or otherwise
make any public disclosure concerning this Agreement or the transactions
contemplated hereby, without prior approval by the other parties hereto (which
approval will not be unreasonably withheld). If any announcement is required by
law to be made by any party hereto, prior to making such announcement such party
will deliver a draft of such announcement to the other parties and shall give
the other parties an opportunity to comment thereon.

         9.13 FURTHER ASSURANCES. Each of the parties shall execute such
documents and perform such further acts (including, without limitation,
obtaining any consents, exemptions, authorizations, or other actions by, or
giving any notices to, or making any filings with, any Governmental Authority or
any other Person) as may be reasonably required or desirable to carry out or to
perform the provisions of this Agreement and/or the Certificate of
Incorporation.

                           [Signature Pages To Follow]

                                       35
<PAGE>

         IN WITNESS WHEREOF, the parties have caused this Agreement to be duly
executed as of the date first above written.

                                     US LEC CORP.

                                     By: /s/ Michael K. Robinson
                                         -----------------------------------
                                     Name:  Michael K. Robinson
                                     Title: Executive Vice President and
                                            Chief Financial Officer

                                     BAIN CAPITAL CLEC INVESTORS, L.L.C.

                                     By:      Bain Capital Fund VI, L.P.,
                                              its Administrative Member
                                     By:      Bain Capital Partners VI, L.P.,
                                              its General Partner
                                     By:      Bain Capital Investors VI, Inc.,
                                              its general partner

                                     By: /s/ Michael A. Krupka
                                         -----------------------------------
                                     Name:
                                     Title: Managing Director

                                     THOMAS H. LEE EQUITY FUND IV, L.P.

                                              By:   THL Equity Advisors IV, LLC,
                                              its general partner

                                     By: /s/ Anthony J. DiNovi
                                         -----------------------------------
                                     Name:  Anthony J. DiNovi
                                     Title: Managing Director

                                       36
<PAGE>

                                     THOMAS H. LEE FOREIGN FUND IV-B, L.P.

                                     By:      THL Equity Advisors IV, LLC,
                                              its general partner

                                     By: /s/ Anthony J. DiNovi
                                         -----------------------------------
                                     Name:  Anthony J. DiNovi
                                     Title: Managing Director

                                     THOMAS H. LEE FOREIGN FUND IV, L.P.

                                     By:      THL Equity Advisors IV, LLC,
                                              its general partner

                                     By: /s/ Scott M. Sperling
                                         -----------------------------------
                                     Name:  Scott M. Sperling
                                     Title: Managing Director

                                     PUTNAM INVESTMENT HOLDINGS, LLC

                                     By: /s/ William H. Woolverton
                                         -----------------------------------
                                     Name:  William H. Woolverton
                                     Title: Managing Director

                                     1997 THOMAS H. LEE NOMINEE TRUST

                                     By: /s/ Gerald Wheeler
                                         -----------------------------------
                                         Trustee

                                       37
<PAGE>

                                     THOMAS H. LEE CHARITABLE
                                     INVESTMENT LIMITED PARTNERSHIP

                                     By: /s/ Thomas H. Lee
                                         -----------------------------------
                                     Name:  Thomas H. Lee
                                     Title: President

                                     /s/ David V. Harkins
                                     -----------------------------------
                                     DAVID V. HARKINS

                                     THE HARKINS 1995 GIFT TRUST

                                     By: /s/ Sheryll J. Harkins
                                         -----------------------------------
                                         Trustee

                                     /s/ Scott A. Schoen
                                     -----------------------------------
                                     SCOTT A. SCHOEN

                                     /s/ C. Hunter Boll
                                     -----------------------------------
                                     C. HUNTER BOLL

                                     /s/ Scott M. Sperling
                                     -----------------------------------
                                     SCOTT M. SPERLING

                                     /s/ Anthony J. DiNovi
                                     -----------------------------------
                                     ANTHONY J. DINOVI

                                     /s/ Thomas M. Hagerty
                                     -----------------------------------
                                     THOMAS M. HAGERTY

                                     /s/ Warren C. Smith, Jr.
                                     -----------------------------------
                                     WARREN C. SMITH, JR.

                                       38
<PAGE>

                                     /s/ Seth W. Lawry
                                     -----------------------------------
                                     SETH W. LAWRY

                                     /s/ Kent R. Weldon
                                     -----------------------------------
                                     KENT R. WELDON

                                     /s/ Terrence M. Mullen
                                     -----------------------------------
                                     TERRENCE M. MULLEN

                                     /s/ Todd M. Abbrecht
                                     -----------------------------------
                                     TODD M. ABBRECHT

                                     /s/ Charles A. Brizius
                                     -----------------------------------
                                     CHARLES A. BRIZIUS

                                     /s/ Scott Jaeckel
                                     -----------------------------------
                                     SCOTT L. JAECKEL

                                     /s/ Soren Oberg
                                     -----------------------------------
                                     SOREN L. OBERG

                                     /s/ Thomas R. Shepherd
                                     -----------------------------------
                                     THOMAS R. SHEPHERD

                                     /s/ Wendy L. Masler
                                     -----------------------------------
                                     WENDY L. MASLER

                                     /s/ Andrew D. Flaster
                                     -----------------------------------
                                     ANDREW D. FLASTER

                                       39
<PAGE>

                                     ROBERT SCHIFF LEE 1988 IRREVOCABLE TRUST

                                     By: /s/ Charles W. Robins
                                         --------------------------------
                                     Trustee:  Charles W. Robins

                                     ------------------------------------
                                     STEPHEN ZACHARY LEE

                                     /s/ Charles W. Robins
                                     --------------------------------
                                     CHARLES W. ROBINS AS CUSTODIAN FOR
                                     JESSE LEE

                                     /s/ Charles W. Robins
                                     --------------------------------
                                     CHARLES W. ROBINS AS CUSTODIAN FOR
                                     NATHAN LEE

                                     /s/ Charles W. Robins
                                     --------------------------------
                                     CHARLES W. ROBINS

                                     /s/ James Westra
                                     --------------------------------
                                     JAMES WESTRA

                                     /s/ Adam A. Abramson
                                     --------------------------------
                                     ADAM A. ABRAMSON

                                     --------------------------------
                                     JOANNE M. RAMOS

                                     /s/ P. Holden Spaht
                                     --------------------------------
                                     P. HOLDEN SPAHT

                                     /s/ Nancy M. Graham
                                     --------------------------------
                                     NANCY M. GRAHAM

                                       40
<PAGE>

                                     /s/ Gregory A. Ciongoli
                                     --------------------------------
                                     GREGORY A. CIONGOLI

                                     /s/ Wm. Matthews Kelly
                                     --------------------------------
                                     WM. MATTHEW KELLY

                                     /s/ K. F. Sullivan
                                     --------------------------------
                                     KEVIN F. SULLIVAN

                                     /s/ Diane M. Barriere
                                     --------------------------------
                                     DIANE M. BARRIERE

                                     /s/ Kim H. Oakley
                                     --------------------------------
                                     KIM H. OAKLEY

                                       41"THE SECURITIES REPRESENTED BY THIS OPTION AGREEMENT HAVE NOT BEEN REGISTERED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANY
STATE AND MAY NOT BE SOLD OR OTHERWISE DISPOSED OF EXCEPT PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT AND APPLICABLE STATE SECURITIES
LAWS OR PURSUANT TO AN APPLICABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS
OF SUCH ACT AND SUCH LAWS."

                                OPTION AGREEMENT

         THIS OPTION AGREEMENT (the "Agreement") is made as of April 11, 2000,
by and between US LEC CORP., a Delaware corporation (the "Company"), and the
Persons whose names are set forth on Schedule 1 attached hereto (individually, a
"Purchaser" and collectively, the "Purchasers")

                              W I T N E S S E T H:

         WHEREAS, the Company and the Purchasers are parties to a Preferred
Stock Purchase Agreement dated as of April 11, 2000 (the "Purchase Agreement");

         WHEREAS, pursuant to the terms and conditions of the Purchase
Agreement, the Company has agreed to sell, and the Purchasers have agreed to
purchase, an aggregate of 200,000 shares of the Company's Series A Convertible
Preferred Stock which are convertible into shares of the Company's Class A
Common Stock, par value $.01 per share (the "Common Stock"); and

         WHEREAS, the parties hereto now wish to provide for an option whereby
the Purchasers shall have the right to purchase an aggregate of up to 100,000
shares of the Preferred Stock (as defined in Article I below), subject to the
terms and conditions contained herein;

         NOW, THEREFORE, in consideration of the foregoing and the
representations, covenants and agreements contained herein, and certain other
good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

<PAGE>
                                    ARTICLE I

                                   DEFINITIONS

         Unless otherwise defined herein, capitalized terms used herein shall
have the meaning given such terms below. Capitalized terms used herein and not
defined shall have the meanings set forth in the Purchase Agreement.

         "ACQUISITION" means (i) the Company has consolidated with, or merged
with or into, any other Person and, in connection with any such consolidation or
merger, the holders of the Company's Common Stock and Class B Common Stock
outstanding immediately prior to such transaction do not own, in the aggregate,
at least 50% of the outstanding stock of the surviving entity in such
transaction, or (ii) any Person has made a tender offer or exchange offer to
acquire all of the Company's outstanding Common Stock and Class B Common Stock
(each such offer, a "Tender Offer"), and, upon the consummation of the Tender
Offer, the holders of the Company's Common Stock and Class B Common Stock
outstanding immediately prior thereto do not own, in the aggregate at least 50%
of the outstanding stock of the Person that made the Tender Offer.

         "ACQUISITION PROPOSAL" means a written proposal submitted to the
Chairman, Chief Executive Officer, President or Chief Financial Officer of the
Company (each, an "Executive Officer") that (i) proposes a transaction that
would, if consummated, result in an Acquisition, (ii) values the Company at not
less than 120% of the Company's market capitalization at the time it is
submitted and (iii) the Executive Officers, after consultation among themselves,
have determined the proposal is a bona fide one that the Company should or is
required to discuss with the Person that submitted it or is then discussing the
proposal with the Person that submitted it.

         "CLOSING" has the meaning assigned thereto in Section 2.2.

         "CLOSING DATE" has the meaning assigned thereto in Section 2.2.

         "COMPANY INDEMNIFIED PARTY" has the meaning assigned thereto in Section
8.1.

         "EXERCISE NOTICE" has the meaning assigned thereto in Section 2.1(a).

         "EXERCISE PERIOD" has the meaning assigned thereto in Section 2.1(c).

         "INVESTOR AGENTS" has the meaning assigned to such term in the
Corporate Governance Agreement.

         "MARKET PRICE" of any security means the average (weighted by daily
trading volume) of the closing prices of such security's sales on all securities
exchanges on which such security may be listed at the time, or, if there has
been no sales on any such exchange on any day, or, if on any day such security
is not so listed, the average of the representative bid and asked prices quoted
in the NASDAQ System as of 4:00 P.M., New York time, or, if on any day such
security is not quoted in the NASDAQ System, the average of the highest bid and
lowest asked prices on such day in the domestic over-the-counter market as
reported by the National Quotation Bureau, Incorporated or any similar successor
organization, in each such case averaged over a period of 30 days consisting of
the day as of which the "Market Price" is being determined and the 29
consecutive Business Days prior to such day. If at any time such security is not
listed on any securities exchange or quoted in the NASDAQ System or the
over-the-counter market, the "Market Price" shall be the fair value thereof
determined jointly by the Company and the Investor Agents. If such parties are
unable to reach agreement within a reasonable period of time, such fair value
shall be determined by an independent appraiser experienced in valuing
securities jointly selected by the Company and the Investor Agents. The
determination of such appraiser shall be final and binding upon the parties, and
the Company shall pay the fees and expenses of such appraiser.

                                       2
<PAGE>

         "OPTION" has the meaning set forth in Section 2.1(a).

         "OPTION PRICE" has the meaning assigned thereto in Section 2.1(a).

         "PREFERRED STOCK" means the Series B Convertible Preferred Stock of the
Company, or any other capital stock of the Company into which such stock is
reclassified or reconstituted.

         "PREMIUM ACQUISITION" means the consummation of an Acquisition that was
the subject of an Acquisition Proposal pursuant to which the holders of the
Company's outstanding Common Stock and Class B Common Stock receive stock, cash
or other consideration having a value on a per share basis at least equal to
110% of the Market Price of the Common Stock on the day the Company first
received such Acquisition Proposal.

         "PURCHASER(S)" has the meaning assigned thereto in the Preamble and
their successors and permitted assigns.

         "PURCHASER PREFERRED STOCK" means the Preferred Stock and the Series A
Preferred Stock.

         "PURCHASER REGULATORY EVENT" means any event in which any Purchaser
becomes subject to regulation as a "carrier," a "telephone company," a "common
carrier," a "public utility," or otherwise under any applicable law or
governmental regulation, federal, state, or local, as a result of the purchase
of the Series A Preferred Stock pursuant to the Purchase Agreement, the purchase
of the Preferred Stock pursuant to this Agreement and the execution and delivery
of the Transaction Documents (as defined in the Purchase Agreement) by the
parties thereto at the closing under the Purchase Agreement.

         "REQUISITE HOLDERS" has the meaning assigned thereto in Section 9.4.

         "SERIES A DESIGNATION" means the Certificate of Designation of the
Company relating to the Series A Preferred Stock filed with the Secretary of
State of Delaware as of the date hereof.

         "SERIES A PREFERRED STOCK" means the Series A Convertible Preferred
Stock of the Company or any other capital stock of the Company into which such
stock is reclassified or reconstituted.

                                       3
<PAGE>

         "SERIES B DESIGNATION" means the Certificate of Designation relating to
the Preferred Stock attached as Exhibit A hereto.

         "SERIES C DESIGNATION" means the Certificate of Designation of the
Company relating to the Series C Preferred Stock to be filed with the Secretary
of State of the State of Delaware in such form as is permitted by the Purchase
Agreement, as amended, supplemented or otherwise modified.

         "SERIES C PREFERRED STOCK" means the Series C Convertible Preferred
Stock of the Company or any other capital stock of the Company into which such
stock is reclassified or reconstituted.

                                   ARTICLE II

                          GRANT AND EXERCISE OF OPTION

         2.1.     GRANT AND EXERCISE OF OPTION; EXERCISE PERIOD.

         (a) The Company hereby grants to each Purchaser named on Schedule 1
hereto an option (the "Option") to purchase, subject to the terms hereof, that
number of shares of Preferred Stock set forth opposite such Purchaser's name on
Schedule 1, at a price of $1,000 per share (the "Option Price"). In the event
some or all of the Purchasers desire to exercise the Option, such Purchasers
shall send to the Company a written notice (the "Exercise Notice" ) specifying
(i) the total number of shares of Preferred Stock each such Purchaser will
purchase pursuant to such exercise and (ii) a date not earlier than five
Business Days nor later than 20 Business Days (subject to extension to satisfy
closing conditions hereunder) from the date of the Exercise Notice for the
closing of such purchase pursuant to Section 2.2. Subject to the provisions of
Section 2.1(c), the Option may be exercised, in whole or in part, at any one
time; provided that the Option may not be exercised in part unless the combined
Option exercises pursuant to the Exercise Notice provide for the purchase of at
least 25,000 shares of Preferred Stock.

         (b) Notwithstanding the provisions of Section 2.1(a), the Company shall
not be obligated to issue and sell any Preferred Stock pursuant to an Exercise
Notice if, within five Business Days of receipt of such notice, the Company
delivers a certificate to the Investor Agents executed by an Executive Officer
stating that, as of the date of receipt of the Exercise Notice, the Company had
received an Acquisition Proposal and describing the material terms of such
Acquisition Proposal (the "Proposal Notice") and provides the Investor Agents
with sufficient documentation to enable them to determine whether the proposed
transaction meets the criteria set forth in the definition of Acquisition
Proposal. If the Company timely delivers a Proposal Notice to the Investor
Agents, the Exercise Notice shall be deemed withdrawn without further action by
the Company or the Purchasers that submitted the Exercise Notice. In the event
(i) the Company terminates discussions with respect to the Acquisition Proposal
that was the subject of the Proposal Notice or (ii) the proposed transaction no
longer meets the criteria set forth in the definition of Premium Acquisition,
the Company shall promptly notify the Investor Agents of that fact in writing
(the "Termination Notice"), in which event the Option may again be exercised,
subject to the terms hereof, including the provisions of this Section 2.1(b) and
Section 2.1(c); provided, however, that in the event of an exercise of the
Option following receipt by the Investor Agents of a Termination Notice pursuant
to clause (ii), the Company shall not close such proposed transaction prior to
the closing of the Option pursuant to Section 2.2. In the event the Company
consummates an Acquisition described in an Acquisition Proposal that was the
subject of a Proposal Notice, it shall promptly notify the Investor Agents of
that fact in writing (the "Consummation Notice") and shall provide the
Purchasers with such documentation as reasonably requested by the Purchasers to
enable them to determine whether such Acquisition constitutes a Premium
Acquisition.

                                       4
<PAGE>

         (c) The Option granted hereunder shall be exercisable in accordance
with the terms hereof by delivery of an Exercise Notice at any time during the
period beginning on the date of this Agreement and ending on April 11, 2001 (the
"Exercise Period"); provided that if the exercise of the Option is deemed to be
withdrawn by the delivery of a Proposal Notice by the Company pursuant to
Section 2.1(b) and either (i) the Investor Agents have received a Termination
Notice with respect to such Proposal Notice or (ii) the Acquisition described in
the Acquisition Proposal that was the subject of such Proposal Notice is
consummated and such Acquisition is not a Premium Acquisition, the Option may be
exercised by delivery of an Exercise Notice at any time until the later of the
expiration of the Exercise Period or 30 days after the receipt by the Investors
Agents of the Termination Notice or Consummation Notice with respect to such
Acquisition, as applicable; and, provided, further, that if the exercise of the
Option is deemed to be withdrawn by the delivery of a Proposal Notice pursuant
to Section 2.1(b) and the Acquisition described in the Acquisition Proposal that
was the subject of such Proposal Notice is consummated and such Acquisition is a
Premium Acquisition, the Option, and the right of any Purchaser to exercise the
Option, shall automatically terminate.

         2.2 CLOSING. The issuance and purchase of the Preferred Stock upon the
exercise of the Option shall take place at the Closing (the "Closing") to be
held at the offices of Moore & Van Allen, PLLC, Charlotte, North Carolina, at
10:00 a.m., on the date specified in the Exercise Notice, or at such other time
and place as the Company and the Purchasers exercising the Option may agree in
writing (the "Closing Date"). At the Closing, the Company shall deliver to the
Purchasers certificates representing the number of shares of the Preferred Stock
specified in the Exercise Notice against delivery to the Company by the
Purchasers of the Option Price therefor by wire transfer of immediately
available funds.

                                   ARTICLE III

             CONDITIONS TO THE OBLIGATION OF THE PURCHASERS TO CLOSE

         The obligation of each Purchaser to purchase the number of shares of
Preferred Stock set forth in the Exercise Notice at the Closing, to pay the
Option Price therefor at the Closing and to perform any other obligations
hereunder shall be subject to the reasonable satisfaction as determined by each
Purchaser of the following conditions on or before the Closing Date:

                                       5
<PAGE>

         3.1 REPRESENTATIONS AND WARRANTIES. The representations and warranties
of the Company contained in Section 5 hereof shall be true and correct (a) when
made and (b) on and as of the Closing Date as if made on and as of such date
except for such changes to Schedules 5.9 and 5.10 as are permitted by the terms
of the Transaction Documents and set forth on revised Schedules 5.9 and 5.10
provided to the Purchasers at the Closing.

         3.2 COMPLIANCE WITH THIS AGREEMENT. The Company shall have performed
and complied in all material respects with all of the agreements, obligations,
covenants and conditions set forth in this Agreement that are required to be
performed or complied with by the Company on or before the Closing Date.

         3.3 OFFICER'S CERTIFICATE. Each Purchaser shall have received a
certificate dated as of the Closing Date from the chief executive officer and
chief financial officer of the Company, substantially in the form of Exhibit B,
to the effect that (a) all representations and warranties of the Company
contained in this Agreement are true and correct, (b) the Company is not in
violation in any material respect of any of the covenants contained in this
Agreement or any other Transaction Document, and (c) all conditions precedent to
the Closing to be performed by the Company have been duly performed in all
material respects.

         3.4 SECRETARY'S CERTIFICATE, GOOD STANDING CERTIFICATES. Each Purchaser
shall have received a certificate from the Company dated the Closing Date and
signed by the Secretary or an Assistant Secretary of the Company, substantially
in the form of Exhibit C, certifying (a) that the attached copies of the
Certificate of Incorporation, Bylaws or other applicable governance documents
and resolutions of the Board of Directors of the Company (i) authorizing the
issuance of the Preferred Stock pursuant to this Agreement and the issuance of
any Common Stock upon conversion thereof and (ii) approving this Agreement and
the transactions contemplated hereby to which it is a party, are all true,
complete and correct and remain unamended and in full force and effect, and (b)
as to the incumbency and specimen signature of each officer of the Company
executing any document delivered in connection with this Agreement on behalf of
the Company.

         3.5 PAYMENT OF FEES. There shall have been paid by the Company (a) to
Bain Capital Partners VI, L.P., a funding fee equal to 1% of the amount funded
by Bain Capital CLEC Investors, L.L.C. at the Closing, (b) to Thomas H. Lee
Equity Advisors IV, L.P. a funding fee equal to 1% of the amount funded by all
Purchasers other than Bain Capital CLEC Investors, L.L.C. at the Closing and (c)
to each Purchaser all legal fees and expenses required to be paid or reimbursed
to such Purchaser by the Company pursuant to Section 9.11 of the Purchase
Agreement. In addition, the Company shall have paid in full all fees due to
First Union Securities, Inc. in connection with the transactions contemplated by
this Agreement as of the Closing.

         3.6 PURCHASE PERMITTED BY APPLICABLE LAWS. The acquisition of and
payment for the Preferred Stock to be acquired by each Purchaser at the Closing
and the consummation of the transactions contemplated hereby at the Closing (a)
shall not be prohibited by any Requirement of Law, and (b) shall not subject any
Purchaser to any penalty or, in its reasonable judgment, other adverse condition
under or pursuant to any Requirement of Law.

                                       6
<PAGE>

         3.7 HSR CLEARANCE. Any required clearance under the Hart-Scott-Rodino
Act to sell the Preferred Stock upon the terms of this Agreement shall have been
obtained.

         3.8 SERIES B DESIGNATION. On or prior to the Closing, the Series B
Designation for the number of shares of Preferred Stock to be delivered at the
Closing, including shares of Preferred Stock issuable as preferential dividends
with respect thereto, shall have been duly filed with the Secretary of State of
the State of Delaware, all in accordance with the applicable provisions of the
DGCL, and the Series B Designation shall constitute a legal and valid amendment
of the Certificate of Incorporation and, as of the Closing, the Certificate of
Incorporation shall not have been otherwise amended; provided, that if at any
time from the date of this Agreement until the Closing Date the Company shall
take any action that would have caused an adjustment in the $46.50 conversion
price in Section 4.2 of the Series B Designation pursuant to Sections 4.3, 4.4,
4.5 or 4.6 thereof if the Series B Preferred Stock had been outstanding, the
conversion price set forth in Section 4.2, at the time the Series B Designation
is filed with the Secretary of State of the State of Delaware on the Closing
Date, shall be the conversion price as so adjusted.

         3.9 PREFERRED STOCK CERTIFICATE. Each Purchaser shall have received
from the Company a duly executed preferred stock certificate, substantially in
the form of Exhibit D, dated the Closing Date representing the number of shares
of Preferred Stock purchased by it at the Closing.

         3.10 REQUIRED CONTRACTUAL CONSENTS. The Company shall have received any
consents required pursuant to the terms of any material Contractual Obligation
in connection with the delivery of the Preferred Stock at the Closing.

         3.11 REQUIRED GOVERNMENTAL CONSENTS. The Company shall have received
all Regulatory Authorizations and other Governmental Authority approvals or
consents required in connection with the delivery of the Preferred Stock at the
Closing.

         3.12 LISTING OF SHARES. The Company shall have filed with The Nasdaq
Stock Market notice of the maximum number of shares of Common Stock potentially
issuable pursuant to the terms of the Series B Designation as of the Closing
Date other than any such shares as may be issuable upon an adjustment in the
conversion price of the Preferred Stock after the Closing Date.

         3.13 OPINIONS OF COUNSEL. The Purchasers shall have received (a) from
Moore & Van Allen, PLLC, special legal counsel for the Company, a favorable
opinion as of the Closing Date, to the effect that: (i) the Company is duly
organized as a corporation under the DGCL; (ii) the Company is validly existing
and in good standing in the jurisdiction of its incorporation and has the
requisite corporate power to own or lease and operate its property, and to carry
on its business as currently conducted; (iii) the issuance of the Preferred
Stock, including the issuance of Preferred Stock as preferential dividends
pursuant to the Series B Designation, has been duly authorized by all corporate
action required under the Company's Organizational Documents; (iv) the Series B
Designation has been duly authorized by all corporate action required under the
Company's Organizational Documents and filed with the Secretary of State of
Delaware; (v) upon issuance at the Closing, the Preferred Stock will be validly
issued, fully paid and nonassessable, and will not have been issued in violation
of or be subject to any preemptive rights, and the issuance of the shares of
Common Stock issuable upon conversion of the Preferred Stock has been duly
authorized and such shares have been duly reserved for issuance, and upon
issuance will be validly issued, fully paid and nonassessable, and will not have
been issued in violation of or be subject to any preemptive rights; and (b) from
Swidler Berlin Shereff Friedman, LLP, special regulatory counsel to the Company,
a favorable opinion as of the Closing Date, to the effect that (i) no consents
or approvals of the FCC or any PUC are required for the purchase of the
Preferred Stock pursuant to this Agreement and (ii) the purchase of the
Preferred Stock pursuant to this Agreement will not, in and of itself, subject
the Purchasers to regulation as common carriers or telephone companies under the
Communications Act (as defined in such opinion) in those states in which the
Company and its Subsidiaries are certified to operate as of the Closing.

                                       7
<PAGE>

         3.14 REGULATORY EVENTS. No Regulatory Event or Purchaser Regulatory
Event shall have occurred and be continuing or shall occur as a result of the
purchase of the Preferred Stock at the Closing.

                                   ARTICLE IV

              CONDITIONS TO THE OBLIGATION OF THE COMPANY TO CLOSE

         The obligations of the Company to issue and sell the Preferred Stock
pursuant to the Exercise Notice at the Closing and to perform its other
obligations hereunder at the Closing shall be subject to the satisfaction as
determined by the Company of the following conditions on or before the Closing
Date:

         4.1 REPRESENTATIONS AND WARRANTIES TRUE. The representations and
warranties of each of the Purchasers contained in Section 6 hereof shall be true
and correct on and as of the Closing Date as if made on and as of such date.

         4.2 COMPLIANCE WITH THIS AGREEMENT. Each of the Purchasers shall have
performed and complied in all material respects with all of its agreements and
conditions set forth or contemplated herein that are required to be performed or
complied with by each of the Purchasers on or before the Closing Date.

         4.3 ISSUANCE PERMITTED BY REQUIREMENTS OF LAWS. The issuance of the
Preferred Stock to be issued by the Company pursuant to the Exercise Notice at
the Closing and the consummation of the transactions contemplated hereby at the
Closing (a) shall not be prohibited by any Requirement of Law and (b) shall not
subject the Company to any penalty or, in its reasonable judgment, other onerous
condition under or pursuant to any Requirement of Law.

         4.4 HSR CLEARANCE. Any required clearance under the Hart-Scott-Rodino
Act to acquire the Preferred Stock pursuant to the Exercise Notice upon the
terms of this Agreement shall have been obtained.

                                       8
<PAGE>

         4.5 OPINION OF COUNSEL. If the rights of any Purchaser to purchase
Preferred Stock hereunder have been Transferred to a Permitted Transferee, such
Permitted Transferee or Permitted Transferees shall have delivered to the
Company an opinion dated the Closing Date from the Permitted Transferees'
counsel, Ropes & Gray, in form and substance satisfactory to the Company and its
counsel, to the effect that each such Permitted Transferee's performance of this
Agreement was duly authorized by the requisite corporate, fiduciary, limited
liability company or partnership action required under its Organizational
Documents and applicable state laws.

                                    ARTICLE V

                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

         The Company hereby represents and warrants to the Purchasers as
follows:

         5.1 ORGANIZATION AND QUALIFICATION. Each of the Company and its
Subsidiaries is duly organized, validly existing and in good standing under the
laws of its state of organization. Each of the Company and its Subsidiaries is
duly qualified to do business and in good standing in each jurisdiction in which
the failure to receive or retain such qualification would reasonably be expected
to have a Material Adverse Effect. As to any such entity that is a limited
liability company, each manager is duly organized, validly existing, in good
standing under the laws of its state of organization, and duly qualified to do
business and in good standing in each jurisdiction in which the failure to
receive or retain such qualification would reasonably be expected to have a
Material Adverse Effect.

         5.2 AUTHORITY AND AUTHORIZATION. Each of the Company and its
Subsidiaries has all requisite corporate or limited liability company right,
power, authority and legal right to carry on its business, to own or lease its
properties and to execute and deliver and perform its obligations under this
Agreement, and, in the case of the Company, to execute and deliver and to
perform its obligations under this Agreement and consummate the transactions
contemplated hereby. The Company's execution, delivery and performance of this
Agreement has been duly and validly authorized by all necessary corporate
proceedings on the part of the Company. Upon issuance, the Preferred Stock, and
any shares of such stock issuable as preferential dividends pursuant to the
terms thereof, will be validly issued, fully paid and nonassessable, and will
not have been issued in violation of or subject to any preemptive rights, and
the shares of Common Stock issuable upon conversion of the Preferred Stock, and
any shares of stock issuable as preferential dividends pursuant to the terms
thereof, have been duly authorized and, as of the date here of, will be reserved
for issuance, and upon issuance will be validly issued, fully paid and
nonassessable, and will not have been issued in violation of or be subject to
any preemptive rights.

                                       9
<PAGE>

         5.3 EXECUTION AND BINDING EFFECT. This Agreement has been duly and
validly executed and delivered by the Company, and constitutes the legal, valid
and binding obligations of the Company enforceable in accordance with its terms,
except as such enforceability may be limited by bankruptcy, insolvency,
reorganization, receivership, moratorium or other laws affecting creditors'
rights generally.

         5.4 GOVERNMENTAL AUTHORIZATIONS. Except as set forth on Schedule 5.4,
no authorization, consent, approval, license, exemption or other action by, and
no registration, qualification, designation, declaration or filing with, any
Governmental Authority is or will be necessary in connection with the execution
and delivery of this Agreement, the consummation by the Company of the
transactions herein contemplated, performance of or compliance by the Company
with the terms and conditions hereof or the legality, validity and
enforceability hereof.

         5.5 NO BROKERAGE FEES. Except for a fee payable to First Union
Securities, Inc., no brokerage or other fee, commission or compensation is to be
paid by the Company or any Subsidiary to any Person in connection with the
transactions hereunder except as contemplated herein.

         5.6 INVESTMENT COMPANY; PUBLIC UTILITY HOLDING COMPANY. Neither the
Company nor any of its Subsidiaries is an "investment company" or a "company
controlled by an investment company" or an "affiliated person" or "promoter" or
"principal underwriter" for, an "investment company," within the meaning of the
Investment Company Act of 1940, as amended, or a "holding company," or a
"subsidiary company" of a "holding company," or an "affiliate" of a "holding
company" or of a "subsidiary company" of a "holding company," within the meaning
of the Public Utility Holding Company Act of 1935, as amended.

         5.7 SECURITIES ACT. Based upon the representations and warranties of
each Purchaser in Section 6 of this Agreement, (i) the Preferred Stock to be
issued pursuant to an Exercise Notice, any Preferred Stock to be issued as
preferential dividends pursuant to the terms thereof and the Common Stock
issuable upon conversion of such Preferred Stock and (ii) the issuance by the
Company thereof, are not required to be registered under the Securities Act or
under the securities or blue sky laws of any state or jurisdiction.

         5.8 ABSENCE OF CONFLICTS. The consummation by the Company of the
transactions contemplated by this Agreement and the performance of or compliance
with the terms and conditions hereof by the Company will not, directly or
indirectly (and with or without notice or the passage of time or both), (a)
violate any Requirements of Law applicable to the Company or its Subsidiaries;
(b) conflict with or result in a breach of or a default under the Organizational
Documents of the Company or its Subsidiaries or any Contractual Obligation to
which the Company or its Subsidiaries is a party or by which such entity or its
properties are bound; (c) result in the creation or imposition of any Lien upon
any property (now owned or hereafter required); or (d) violate or conflict with,
or give any Governmental Authority the right to challenge the transactions
contemplated by this Agreement or revoke, withdraw, suspend, cancel, terminate
or modify, any Regulatory Authorization issued to or held by the Company or any
Subsidiary (other than as set forth on Schedule 5.8).

                                       10
<PAGE>

         5.9 TRANSACTIONS WITH AFFILIATES. No Affiliate and no officer or
director of either the Company or any its Subsidiaries or any individual related
by blood, marriage, adoption or otherwise to any such Affiliate, officer or
director, or any Person in which any such Affiliate, officer, director or
individual related thereto owns any material beneficial interest, is a party to
any agreement, contract, commitment or transaction with the Company or any of
its Subsidiaries or has any material interest in any material property used by
the Company or any of its Subsidiaries, except as set forth on Schedule 5.9.

         5.10 CAPITALIZATION. The authorized capital stock of the Company and
its Subsidiaries and the issued and outstanding shares thereof are as described
on Schedule 5.10. As of the Closing Date, all outstanding shares of capital
stock of the Company and its Subsidiaries will be duly authorized and validly
issued, fully paid, nonassessable and free and clear of any Lien created by the
Company or any Subsidiary thereof (other than Liens under the Senior Loan
Documents). Except as described in Schedule 5.10, no other class of capital
stock or other ownership interests of the Company or its Subsidiaries are
authorized or outstanding. Neither the Company nor any Subsidiary is subject to
any obligation (contingent or otherwise) to repurchase, redeem or otherwise
acquire its capital stock or any warrants, options or other rights to acquire
its capital stock, except pursuant to the Series A Designation and, when filed
with the Secretary of State of Delaware, the Series B Designation and Series C
Designation. The Company does not have any outstanding securities convertible
into capital stock of the Company (other than the Class B Common Stock and the
Series A Preferred Stock); and except for shares of Common Stock reserved for
issuance upon the exercise of outstanding warrants or in connection with the
Company Stock Option Plan, the Company does not have any shares of capital stock
reserved for issuance (other than shares of Common Stock reserved for issuance
upon conversion of the Class B Common Stock, the Preferred Stock, Series A
Preferred Stock and Series C Preferred Stock). Except as set forth on Schedule
5.10 and other than the Company's outstanding warrants and stock options and
this Agreement, the Company does not have any commitment to authorize, issue or
sell any of its capital stock or securities convertible into or exchangeable for
any of its capital stock. Neither the Company nor any of its Subsidiaries is a
party to any "phantom stock", employee stock option plan, other equity-based
incentive plan or similar agreement, other than the Company Stock Option Plan.
Schedule 5.10 sets forth the number of shares of capital stock reserved for
issuance upon the exercise of options granted or available to be granted under
the Company Stock Option Plan. Schedule 5.10 also lists all of the Company's
outstanding warrants to purchase capital stock. Except as set forth on Schedule
5.10, there are no preemptive or similar rights to purchase or otherwise acquire
equity securities of, or interests in, the Company or any of its Subsidiaries
pursuant to any Requirements of Law or Contractual Obligations applicable to the
Company or any of its Subsidiaries. Other than as set forth in the Transaction
Documents, there are no existing rights with respect to registration or sale or
resale under the Securities Act or the securities or blue sky laws of any state
or jurisdiction of any securities of the Company or any of its Subsidiaries.
Subject to the provisions of Section 3.8, the shares of Preferred Stock to be
issued to each Purchaser on the Closing Date, and any additional shares of
Preferred Stock to be issued as preferential dividends pursuant to the terms
thereof, will upon issuance to such Purchaser have the designation, preferences,
qualifications, limitations, restrictions and such special and relevant rights
as are set forth in the Series B Designation.

                                       11
<PAGE>

         5.11 COMMISSION FILINGS. Since April 23, 1998 (the date of the
Company's initial public offering), the Company has filed with the Commission,
on a timely basis, all registration statements, reports on Form 10-K, 10-Q and
8-K, proxy statements and information statements, and other documents that it
was required to file under the Securities Act or the Exchange Act. As of the
respective dates of such filings, none of the Company's filings with the
Commission contained (and the Company's most recent Form 10-K does not contain)
an untrue statement of a material fact or omitted (and the Company's most recent
Form 10-K does not omit) to state any material fact necessary to make any
statement of a material fact that it contained, in light of the circumstances in
which made, not misleading; and when filed with the Commission, each of such
filings with the Commission complied in all material respects with the
applicable requirements of the Securities Act or Exchange Act, as applicable.
The Company is eligible to file a registration statement on Form S-3 and has
taken all actions which would be required to permit sales of its securities
pursuant to Rule 144 under the Securities Act.

         5.12 LITIGATION. There is no pending or, to the Company's knowledge,
threatened action, suit or proceeding that challenges the transactions
contemplated by this Agreement or that would have the effect of preventing,
delaying, making illegal or otherwise interfering with the transactions
contemplated by this Agreement.

         5.13 NO DEFAULT. To the Company's knowledge, no event has occurred or
circumstance exists that (with or without notice or the passage of time or both)
would constitute or result in a violation or breach by the Company or any
Subsidiary of any provisions of the Transaction Documents.

                                   ARTICLE VI

                REPRESENTATIONS AND WARRANTIES OF THE PURCHASERS

         Each Purchaser as to itself and not as to any other Purchaser hereby
severally represents and warrants to the Company, as appropriate, as follows:

         6.1 AUTHORIZATION; NO CONTRAVENTION. Such Purchaser (unless an
individual) is duly organized, validly existing and in good standing as a
corporation, limited liability company or general or limited partnership under
the laws of the state of its incorporation or formation. The execution, delivery
and performance by such Purchaser of this Agreement (a) is within such
Purchaser's power and authority and has been duly authorized by all necessary
partnership, company or corporate action, (b) does not contravene the terms of
such Purchaser's organizational documents or any amendment thereof and (c) will
not violate, conflict with or result in any breach or contravention of any
material Contractual Obligation of such Purchaser, or any material Requirement
of Law directly relating to such Purchaser.

         6.2 BINDING EFFECT. This Agreement has been duly executed and delivered
by such Purchaser, and this Agreement constitutes the legal, valid and binding
obligation of such Purchaser enforceable against it in accordance with its
terms, except as enforceability may be limited by applicable bankruptcy,
insolvency, reorganization, moratorium, fraudulent conveyance or other similar
laws affecting the enforcement of creditors' rights generally or by general
equitable principles relating to enforceability.

                                       12
<PAGE>

         6.3 ACCREDITED INVESTOR; PURCHASE FOR OWN ACCOUNT. Such Purchaser is an
"accredited investor" within the meaning of Regulation D under the Securities
Act. The Preferred Stock to be issued pursuant to the terms of this Agreement,
any Preferred Stock to be issued as preferential dividends pursuant to the terms
thereof and the shares of Common Stock to be issued upon conversion of such
Preferred Stock are being or will be acquired for its own account and with no
intention of distributing or reselling such securities or any part thereof in
any transaction that would be in violation of the Securities Act or the
securities laws of any state, without prejudice, however, to the rights of such
Purchaser at all times to sell or otherwise dispose of all or any part of such
Preferred Stock or any shares of Common Stock under an effective registration
statement under the Securities Act, or under an exemption from such registration
available under the Securities Act. If such Purchaser should in the future
decide to dispose of such Preferred Stock or any shares of Common Stock issued
upon conversion of the Preferred Stock, such Purchaser understands and agrees
that it may do so only in compliance with the Securities Act and applicable
state securities laws, as then in effect. Such Purchaser agrees to the
imprinting, so long as required by law, of a legend on certificates representing
such Preferred Stock or any shares of Common Stock issued upon conversion of the
Preferred Stock to the following effect:

         "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
         REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE
         SECURITIES LAWS OF ANY STATE AND MAY NOT BE SOLD OR OTHERWISE DISPOSED
         OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH
         ACT AND APPLICABLE STATE SECURITIES LAWS OR PURSUANT TO AN APPLICABLE
         EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND SUCH
         LAWS."

         The requirement to include the legend set forth above shall cease and
terminate as to any particular shares of Preferred Stock or Common Stock (a)
when, in the opinion of Ropes & Gray, or other counsel reasonably acceptable to
the Company, such legend is no longer required in order to assure compliance by
the Company with the Securities Act or (b) when such shares have been
effectively registered under the Securities Act or transferred pursuant to Rule
144. Whenever (x) such requirement shall cease and terminate as to any such
shares or (y) such shares shall be transferable under paragraph (k) of Rule 144,
the holder thereof shall be entitled to receive from the Company, without
expense, new certificates not bearing the legend set forth above.

         Such Purchaser also agrees to the imprinting, so long as required by
law, of a legend on certificates representing its shares of Preferred Stock:

         "THESE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE TERMS
         AND CONDITIONS, INCLUDING CERTAIN TRANSFER RESTRICTIONS, OF EACH OF
         THAT CERTAIN CORPORATE GOVERNANCE AGREEMENT, DATED AS OF APRIL 11,
         2000, AMONG THE COMPANY AND CERTAIN OF THE COMPANY'S STOCKHOLDERS. A
         COPY OF SUCH AGREEMENT MAY BE OBTAINED AT NO COST BY WRITTEN REQUEST TO
         THE COMPANY MADE BY THE HOLDER OF THIS CERTIFICATE."

                                       13
<PAGE>

         6.4 GOVERNMENTAL AUTHORIZATIONS. Except for clearance under the
Hart-Scott-Rodino Act, no notice to, consent of, or registration, filing or
declaration with, any Governmental Authority is required in connection with such
Purchaser's execution, delivery and performance of this Agreement and the
consummation of the transactions contemplated hereby.

         6.5 NO BROKERS OR FINDERS. Except as disclosed on Schedule 6.5, no
agent, broker, finder, or investment or commercial banker or other Person or
firm engaged by or acting on behalf of such Purchaser in connection with the
negotiation, execution or performance of this Agreement or the transactions
contemplated herein is or will be entitled to any brokerage or finder's or
similar fee or other commission as a result of this Agreement or such
transaction.

         6.6 VOTING AND OTHER AGREEMENTS. Such Purchaser does not have any
agreements, arrangements or understandings with any other Person (other than
with other Purchasers who are Affiliates of such Purchaser) with regard to
acquiring, holding, voting or disposing of the securities of the Company other
than as set forth in the Transaction Documents to which such Purchaser is a
party.

                                   ARTICLE VII

                                    COVENANTS

         7.1 HSR CLEARANCE. The Company and each of the Purchasers shall
cooperate with and provide each other, respectively, with any information that
each party reasonably requires and file such notices and responses as may be
necessary to enable each party to obtain any required clearance under the
Hart-Scott-Rodino Act in connection with the exercise of the Option. Each such
Purchaser required to obtain such clearance agrees to use all reasonable best
efforts to obtain such clearance as promptly as practicable on or prior to the
Closing Date.

         7.2 RESERVATION OF SHARES. The Company shall at all times reserve and
keep available out of the aggregate of its authorized but unissued shares, free
of preemptive rights, (i) such number of its duly authorized shares of Preferred
Stock as shall be sufficient to enable the Company to pay preferential dividends
pursuant to the terms of the Series B Designation with respect to all shares of
Preferred Stock issued thereunder, and (ii) such number of its duly authorized
shares of Common Stock as shall be sufficient to enable the Company to issue
Common Stock upon conversion of all such Preferred Stock.

         7.3 NOTICE OF ADJUSTMENTS. The Company shall give each of the
Purchasers written notice of any adjustments in the conversion price of the
Series B Designation contemplated by Section 3.8 within 10 Business Days of the
adjustment.

                                       14
<PAGE>

         7.4 GOVERNMENTAL CONSENTS. The Company shall use all commercially
reasonable efforts to obtain all of the authorizations, consents, approvals,
licenses and/or exemptions necessary in connection with the Closing hereunder,
including those listed on Schedule 5.4, on or prior to the Closing Date.

         7.5 CORPORATE CHANGE. Prior to the Closing Date, the Company shall:

         (a) prior to the consummation of any Corporate Change (as defined in
the Series B Designation) in which the Company is the successor or purchasing
corporation, make appropriate provisions (in form and substance reasonably
satisfactory to the Purchasers) such that each Purchaser shall have the right to
receive upon exercise of the Option, the Preferred Stock into which such Option
is exercisable with such terms and rights as would otherwise have been
applicable if the provisions of Section 4 and 5 of the Series B Designation had
been in full force and effect with respect to such shares since the date of this
Agreement; and

         (b) prior to the consummation of any Corporate Change in which the
successor or purchasing corporation is an entity other than the Company, make
appropriate provisions (in form and substance reasonably satisfactory to the
Purchasers) to ensure that each Purchaser shall have the right to receive upon
exercise of the Option, the number of shares of convertible preferred stock into
which such Option is exercisable to be issued by such successor or purchasing
corporation with substantially the same terms and rights as the Preferred Stock
as otherwise would have been applicable if the provisions of Section 4 and 5 of
the Series B Designation had been in full force and effect with respect to such
shares since the date of this Agreement.

         7.6 BEST EFFORTS. The Company will, and will cause each of its
Affiliates to, use its best efforts to cause the conditions set forth in Article
III to be satisfied on or prior to the Closing.

         7.7 ADJUSTMENTS IN CERTIFICATE OF DESIGNATION. The parties hereto agree
that upon the exercise of the Option, the terms of the Series B Designation
attached as Exhibit A hereto (including without limitation, the rate in clause
(i) of the definition of "Applicable Rate" and the number of "Dividend Payment
Dates" on which the Corporation is required to pay preferential dividends
through the issuance of additional shares of Preferred Stock) shall be adjusted
such that as of the twelfth dividend payment date under the Series A
Designation, the holders of each share of the Preferred Stock will have received
as preferential dividends thereon 0.19562 additional shares of Preferred Stock.
Such adjustments must be on terms reasonably satisfactory to each of the parties
hereto. The Series B Designation (as so adjusted) shall thereafter be referred
to herein as the "Series B Designation" and shall be filed with the Secretary of
State of Delaware in accordance with Section 3.8 hereof.

                                       15
<PAGE>

                                  ARTICLE VIII

                          INDEMNIFICATION; TERMINATION

         8.1 INDEMNIFICATION. Effective upon the Closing, the Company agrees to
indemnify and hold harmless the Purchasers and their Affiliates and their
officers, directors, agents, employees, subsidiaries, partners and controlling
Persons (each, a "Company Indemnified Party") to the fullest extent permitted by
law, from and against any and all losses, demands, actions, costs, claims,
damages, expenses (including reasonable fees, disbursements and other charges of
counsel) or other liabilities (collectively, "Company Liabilities") incurred or
suffered by such Company Indemnified Party resulting from or arising out of (i)
any misrepresentation or breach of any representation or warranty of the Company
in this Agreement, or any certificate or instrument delivered pursuant hereto,
(ii) any breach of any covenant or obligation of the Company in this Agreement,
or (iii) any investigation or proceeding against the Company or any Company
Indemnified Party that arises out of or in connection with this Agreement,
whether or not the transactions contemplated by this Agreement are consummated,
which investigation or proceeding requires the participation of, or is commenced
or filed against, any Company Indemnified Party because of this Agreement or the
transactions contemplated hereby; provided that (x) the Company shall not be
liable under Section 8.1(iii) to a Company Indemnified Party for any liabilities
resulting primarily from any actions that involved the gross negligence or
willful misconduct or any Company Indemnified Party or the breach by any Company
Indemnified Party of any representation, warranty, covenant or other agreement
of such Indemnified Party contained herein.

         8.2 NOTIFICATION. The Company Indemnified Party, under Section 8.1(iii)
will, promptly after the receipt of notice of the commencement of any action,
investigation, claim or other proceeding against such Company Indemnified Party
in respect of which indemnity may be sought from the Company under Section
8.1(iii), notify the Company in writing of the commencement thereof. The
omission of any Company Indemnified Party so to notify the Company of any such
action shall not relieve the Company from any liability which it may have to
such Company Indemnified Party under Section 8.1(iii) unless, and only to the
extent that, such omission results in the Company's forfeiture of substantive
rights or defenses or the Company is otherwise irrevocably prejudiced in
defending such proceeding. In case any such action, claim or other proceeding
shall be brought against any Company Indemnified Party and it shall notify the
Company of the commencement thereof, the Company shall be entitled to assume the
defense thereof at its own expense, with counsel satisfactory to the Company
Indemnified Party; provided, that any Company Indemnified Party may, at its own
expense, retain separate counsel to participate in such defense. Notwithstanding
the foregoing, in any action, claim or proceeding in which both the Company, on
the one hand, and a Company Indemnified Party, on the other hand, is, or is
reasonably likely to become, a party, such Company Indemnified Party shall have
the right to employ separate counsel at the Company's expense and to control its
own defense of such action, claim or proceeding if, (a) the Company has failed
to assume the defense and employ counsel as provided herein, (b) the Company has
agreed in writing to pay such fees and expenses of separate counsel or (c) in
the reasonable opinion of counsel to such Company Indemnified Party, a conflict
or likely conflict exists between the Company, on the one hand, and such Company
Indemnified Party, on the other hand, that would make such separate
representation advisable, provided, however, that the Company shall not in any
event be required to pay the fees and expenses of more than one separate counsel
(and if deemed necessary by such separate counsel, appropriate local counsel who
shall report to such separate counsel). The Company agrees that it will not,
without the prior written consent of a Company Indemnified Party, settle,
compromise or consent to the entry of any judgment in any pending or threatened
claim, action or proceeding relating to the matters contemplated hereby (if such
Company Indemnified Party is a party thereto or has been actually threatened to
be made a party thereto) unless such settlement, compromise or consent includes
an unconditional release of such Company Indemnified Party from all liability
arising or that may arise out of such claim, action or proceeding. The Company
shall not be liable for any settlement of any claim, action or proceeding
effected against a Company Indemnified Party without the prior written consent
of the Company.

                                       16
<PAGE>

                                   ARTICLE IX

                                  MISCELLANEOUS

         9.1 CLAIMS AND SUITS UNDER SECTION 8.1. No claim may be made or suit
instituted under Section 8.1 with respect to any breach of a representation or
warranty (except if it relates to Sections 5.1, 5.2, 5.3, 5.10 or if it relates
to fraud) after the date that is eighteen (18) months after the Closing Date,
unless the Company Indemnified Party has given the indemnifying party written
notice of such claim or suit (describing with reasonable specificity the amount
of and basis for such claim or suit) on or prior to such date.

         9.2 NOTICES. All notices, claims, demands and other communications
("Notices") provided for or permitted hereunder shall be made in writing and
shall be by registered or certified first class mail, return receipt requested,
telecopier, recognized overnight courier service or personal delivery:

         (a)      if to the Company:

                           US LEC Corp.
                           Transamerica Square
                           401 N. Tryon Street, Suite 1000
                           Charlotte, North Carolina 28202
                           Attention:  General Counsel
                           Telecopier:  (704) 319-3098

                  with a required copy to:

                           Moore & Van Allen, PLLC
                           100 North Tryon Street, Floor 47
                           Charlotte, North Carolina 28202-4003
                           Attention:  Barney Stewart III
                           Telecopier:  (704) 331-1151

                                       17
<PAGE>

         (b)      if to the Purchasers or the Investor Agents:

                           Bain Capital, Inc.
                           Two Copley Place
                           Boston, Massachusetts 02116
                           Attention:  Ian K. Loring
                           Telecopier:  (617) 572-3274

                           and to:

                           Thomas H. Lee Partners, L.P.
                           75 State Street, 26th Floor
                           Boston, Massachusetts 02109
                           Attention:  Anthony J. DiNovi
                           Telecopier (617) 227-3514

                  with a required copy to:

                           Ropes & Gray
                           One International Plaza
                           Boston, Massachusetts 02110-2624
                           Attention:  Philip J. Smith
                           Telecopier:  (617) 951-7050

         All Notices shall be deemed to have been duly given: when delivered by
hand, if personally delivered; when delivered by courier, if delivered by
commercial overnight courier service; five Business Days after being deposited
in the mail, postage prepaid, if mailed; and when receipt is acknowledged by the
individual to whom the telecopy is sent, if telecopied.

         9.3 SUCCESSORS AND ASSIGNS. This Agreement shall inure to the benefit
of and be binding upon the successors and permitted assigns of the parties
hereto. Subject to applicable securities laws and except as otherwise set forth
in the Transaction Documents (including, without limitation, the Corporate
Governance Agreement), the Purchasers may assign any of their rights under this
Agreement, to any Person who is a Permitted Transferee. The Company may not
assign any of its rights under this Agreement without the prior written consent
of the Purchasers. Except as provided in Article 9, no Person other than the
parties hereto and their successors and permitted assigns is intended to be a
beneficiary of this Agreement.

         9.4 DETERMINATIONS, REQUESTS OR CONSENTS. Any amendment, supplement or
modification of or to any provision of this Agreement, any waiver of any
provision of this Agreement, and any consent to any departure of the Company
from the terms of any provision of this Agreement, shall be effective (a) only
if it is made or given in writing and signed by the Company and the Required
Holders (as defined below) in accordance with this Section 9.4, and (b) only in
the specific instance and for the specific purpose for which made or given. All
determinations, requests, consents, waivers or amendments to be made by the
Purchasers in their opinion or judgment or with their approval or otherwise
pursuant to this Agreement shall be made at any time prior to the Closing by the
holders of at least 51% of the Series A Convertible Preferred Stock then
outstanding, and following the Closing by the holders of at least 51% of the
Purchaser Preferred Stock then outstanding (the "Required Holders").

                                       18
<PAGE>

         9.5 COUNTERPARTS. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

         9.6 HEADINGS. The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

         9.7 GOVERNING LAW. This agreement shall be governed by and construed in
accordance with the laws of the State of Delaware without regard to the
principles of conflicts of law of such state.

         9.8 SEVERABILITY. If any one or more of the provisions contained
herein, or the application thereof in any circumstance, is held invalid, illegal
or unenforceable in any respect for any reason, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions hereof shall not be in any way impaired, unless the provisions held
invalid, illegal or unenforceable shall substantially impair the benefits of the
remaining provisions hereof.

         9.9 RULES OF CONSTRUCTION. Unless the context otherwise requires, "or"
is not exclusive, and references to sections or subsections refer to sections or
subsections of this Agreement. All pronouns and any variations thereof refer to
the masculine, feminine or neuter, singular or plural, as the context may
require.

         9.10 ENTIRE AGREEMENT. This Agreement, together with the exhibits
hereto and the other Transaction Documents, is intended by the parties as a
final expression of their agreement and intended to be a complete and exclusive
statement of the agreement and understanding of the parties hereto in respect of
the subject matter contained herein and therein. There are no restrictions,
promises, warranties or undertakings, other than those set forth or referred to
herein or therein. This Agreement, together with the exhibits hereto, and the
other Transaction Documents supersede all prior contemporaneous agreements and
understandings between the parties with respect to such subject matter.

         9.11 FURTHER ASSURANCES. Each of the parties shall execute such
documents and perform such further acts (including, without limitation,
obtaining any consents, exemptions, authorizations, or other actions by, or
giving any notices to, or making any filings with, any Governmental Authority or
any other Person) as may be reasonably required or desirable to carry out or to
perform the provisions of this Agreement.

                           [Signature Pages To Follow]

                                       19
<PAGE>

                                       20
<PAGE>

         IN WITNESS WHEREOF, the parties have caused this Agreement to be duly
executed as of the date first above written.

                                  US LEC CORP.

                                    By: /s/ Michael K. Robinson
                                         Name:  Michael K. Robinson
                                                -----------------------------
                                         Title: Executive Vice President and
                                                  Chief Financial Officer

                                    BAIN CAPITAL CLEC INVESTORS, L.L.C.

                                    By:      Bain Capital Fund VI, L.P.,
                                             its Administrative Member
                                    By:      Bain Capital Partners VI, L.P.,
                                             its General Partner
                                    By:      Bain Capital Investors VI, Inc.,
                                             its general partner

                                    By: /s/ Michael A. Krupka
                                        -----------------------------
                                         Name:  Michael A. Krupka
                                         Title: Managing Director

                                    THOMAS H. LEE EQUITY FUND IV, L.P.

                                    By:      THL Equity Advisors IV, LLC,
                                             -----------------------------
                                             its general partner

                                    By: /s/ Anthony J. DiNovi
                                        -----------------------------
                                         Name:  Anthony J. DiNovi
                                         Title: Managing Director

                                    THOMAS H. LEE FOREIGN FUND IV-B, L.P.

                                    By:      THL Equity Advisors IV, LLC,
                                             its general partner

                                    By: /s/ Anthony J. DiNovi
                                        -----------------------------
                                         Name:  Anthony J. DiNovi
                                         Title: Managing Director

                                       21
<PAGE>

                                    THOMAS H. LEE FOREIGN FUND IV, L.P.

                                    By:      THL Equity Advisors IV, LLC,
                                             its general partner

                                    By: /s/ Scott M. Sperling
                                        -----------------------------
                                         Name:  Scott M. Sperling
                                         Title: Managing Director

                                    PUTNAM INVESTMENTS, INC.

                                    By: /s/ William H. Woolverton
                                        -----------------------------
                                         Name:  William H. Woolverton
                                         Title: Managing Director

                                    1997 THOMAS H. LEE NOMINEE TRUST

                                    By: /s/ Gerald Wheeler
                                        -----------------------------
                                        Trustee

                                    THOMAS H. LEE CHARITABLE INVESTMENT L.P.

                                    By: /s/ Thomas H. Lee
                                        -----------------------------
                                         Name:  Thomas H. Lee
                                         Title: President

                                       22
<PAGE>

                                    /s/ David V. Harkins
                                    -----------------------------
                                    DAVID V. HARKINS

                                    THE HARKINS 1995 GIFT TRUST

                                    By: /s/ Sheryll J. Harkins
                                        -----------------------------
                                         Trustee

                                    /s/ Scott A. Schoen
                                    -----------------------------
                                    SCOTT A. SCHOEN

                                    /s/ C. Hunter Boll
                                    -----------------------------
                                    C. HUNTER BOLL

                                    /s/ Scott M. Sperling
                                    -----------------------------
                                    SCOTT M. SPERLING

                                    /s/ Anthony J. DiNovi
                                    -----------------------------
                                    ANTHONY J. DINOVI

                                    /s/ Thomas M. Hagerty
                                    -----------------------------
                                    THOMAS M. HAGERTY

                                    /s/ Warren C. Smith, Jr.
                                    -----------------------------
                                    WARREN C. SMITH, JR.

                                    /s/ Seth W. Lawry
                                    -----------------------------
                                    SETH W. LAWRY

                                    /s/ Kent R. Weldon
                                    -----------------------------
                                    KENT R. WELDON

                                       23
<PAGE>

                                    /s/ Terrence M. Mullen
                                    -----------------------------
                                    TERRENCE M. MULLEN

                                    /s/ Todd M. Abbrecht
                                    -----------------------------
                                    TODD M. ABBRECHT

                                    /s/ Charles A. Brizius
                                    -----------------------------
                                    CHARLES A. BRIZIUS

                                    /s/ Scott Jaeckel
                                    -----------------------------
                                    SCOTT JAECKEL

                                    /s/ Soren Oberg
                                    -----------------------------
                                    SOREN OBERG

                                    /s/ Thomas R. Shepherd
                                    -----------------------------
                                    THOMAS R. SHEPHERD

                                    /s/ Wendy L. Masler
                                    -----------------------------
                                    WENDY L. MASLER

                                    /s/ Andrew D. Flaster
                                    -----------------------------
                                    ANDREW D. FLASTER

                                    ROBERT SCHIFF LEE 1988 IRREVOCABLE TRUST

                                    By: /s/ Charles W. Robins
                                        -----------------------------
                                         Trustee

                                    /s/ Stephen Zachary Lee
                                    -----------------------------
                                    STEPHEN ZACHARY LEE

                                       24
<PAGE>

                                    /s/ Charles W. Robins
                                    -----------------------------
                                    CHARLES W. ROBINS AS CUSTODIAN FOR
                                    JESSE LEE

                                    /s/ Charles W. Robins
                                    -----------------------------
                                    CHARLES W. ROBINS AS CUSTODIAN FOR
                                    NATHAN LEE

                                    /s/ Charles W. Robins
                                    -----------------------------
                                    CHARLES W. ROBINS

                                    /s/ James Westra
                                    -----------------------------
                                    JAMES WESTRA

                                    THL-CCI INVESTORS LIMITED
                                    PARTNERSHIP

                                    By:      THL Investment Management Corp.,
                                             its general partner

                                    By:
                                         -----------------------------
                                         Name:
                                         Title:

                                    /s/ Adam A. Abramson
                                    -----------------------------
                                    ADAM A. ABRAMSON

                                    /s/ Joanne M. Ramos
                                    -----------------------------
                                    JOANNE M. RAMOS

                                    /s/ P. Holden Spaht
                                    -----------------------------
                                    P. HOLDEN SPAHT

                                    /s/ Nancy M. Graham
                                    -----------------------------
                                    NANCY M. GRAHAM

                                    /s/ Gregory A. Ciongoli
                                    -----------------------------
                                    GREGORY A. CIONGOLI

                                       25
<PAGE>

                                    /s/ Wm. Matthew Kelly
                                    -----------------------------
                                    WM. MATTHEW KELLY

                                    /s/ Kevin F. Sullivan
                                    -----------------------------
                                    KEVIN F. SULLIVAN

                                    /s/ Diane M. Barriere
                                    -----------------------------
                                    DIANE M. BARRIERE

                                    /s/ Kim H. Oakley
                                    -----------------------------
                                    KIM H. OAKLEY

                                       26

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