<PAGE>   1
                          e.spire COMMUNICATIONS, INC.

                               UNITS CONSISTING OF

                      SERIES A CONVERTIBLE PREFERRED STOCK

                                       AND

                   WARRANTS TO PURCHASE SHARES OF COMMON STOCK



                               PURCHASE AGREEMENT

                                                          March 1, 2000


To:      Northern Trust Company, as Trustee for the
         Honeywell International Inc.
         Master Retirement Trust
         50 South LaSalle Street
         Chicago, IL 60675


Ladies and Gentlemen:

                  e.spire COMMUNICATIONS, INC. (the "Company"), a Delaware
corporation, hereby confirms its agreement with the HONEYWELL INTERNATIONAL
INC. MASTER RETIREMENT TRUST acting through its trustee, the Northern Trust
Company (the "Purchaser"), as set forth below.

                  1. The Securities. Subject to the terms and conditions herein
contained, the Company hereby agrees to issue and sell to the Purchaser and the
Purchaser hereby agrees to purchase from the Company up to an aggregate of
50,000 Units (hereinafter defined) at a price of $1,000 per Unit (or $792.29 per
share of Preferred Stock (hereinafter defined) and $207.71 per Warrant
(hereinafter defined)) for an aggregate purchase price of $50 million. Each Unit
shall consist of one (1) share of Series A Convertible Preferred Stock of the
Company par value $1.00 per share (collectively, the "Preferred Stock"), each
share of which Preferred Stock is initially convertible into 126.42225 shares of
the common stock, par value
<PAGE>   2
                                      - 2 -


$.01 per share (the "Common Stock") of the Company at a conversion price of
$7.91 per share, subject to adjustment as provided in the Transaction Documents
(hereinafter defined) and one (1) Warrant in the form attached as Exhibit A
hereto (collectively, the "Warrants," and, together with the Preferred Stock,
the "Units"), each of which Warrants is initially exercisable to purchase 44.1
shares (the "Warrant Shares") of the Common Stock at an exercise price of $9.89
per share, subject to adjustment as provided in Section 6(d) and as provided in
the Warrant Agreement (hereinafter defined). The Preferred Stock shall upon
issuance have the rights and preferences set forth in the Certificate of
Designation ("Certificate of Designation") attached hereto as Exhibit B. The
Units, the Preferred Stock and the Warrants are herein collectively referred to
as the "Securities."

                  The Securities will be offered and sold to the Purchaser
without being registered under the Securities Act of 1933, as amended (the
"Act"), in reliance upon one or more exemptions therefrom.

                  The Purchaser and the direct and indirect transferees of the
Securities will be entitled to the benefits of (i) the Registration Rights
Agreement substantially in the form attached hereto as Exhibit C (the
"Registration Rights Agreement"), among the Company and the other signatories
thereto, which will require the Company, among other things, to file with the
Securities and Exchange Commission (the "Commission") a shelf registration
statement (the "Registration Statement") pursuant to Rule 415 under the Act
relating to the resale of the Preferred Stock and shares of Common Stock
issuable in connection with the conversion thereof (collectively, the
"Conversion Shares" and, together with the Warrant Shares and the Additional
Warrant Shares (hereinafter defined), the "Additional Securities") and to use
its reasonable best efforts to cause such registration statement to be declared
and remain effective in accordance therewith and (ii) the Warrant Agreement
among the Company and the other signatories thereto substantially in the form
attached hereto as Exhibit D (the "Warrant Agreement") which will require the
Company, among other things, to file with the Commission a registration
statement (the "Warrant Registration Statement") pursuant to Rule 415 under the
Securities Act relating to the resale of the Warrants and Warrant Shares and to
use its reasonable best efforts to cause such registration statement to be
declared and remain effective in accordance therewith.

                  This purchase agreement (the "Agreement"), the Certificate of
Designation, the Warrant Agreement and related Warrants and the Registration
Rights Agreement are herein collectively referred to as the "Transaction
Documents."

                  2. Representations and Warranties of the Company. The Company
represents and warrants to and agrees with the Purchaser that:
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                                      - 3 -


         (a) Since January 1, 1999 and to the date of this Agreement, the
Company has filed with the Commission, a Proxy Statement on Schedule 14A with
respect to the Company's 1999 Annual Meeting of Stockholders, the Company's
Annual Report on Form 10-K for the year ended December 31, 1998, the Company's
Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31, June 30
and September 30, 1999, respectively, and the Company's Current Reports on Form
8-K dated February 22, 1999, July 8, 1999, October 28, 1999, November 1, 1999,
December 3, 1999 and February 1, 2000 (including all exhibits to any of such
documents) (collectively the "SEC Reports"), which constitute all reports,
schedules, forms, statements and other documents required to be filed with the
Commission during such period by the Company. As of their respective dates, the
SEC Reports complied in all material respects with the requirements of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and the rules
and regulations of the Commission promulgated thereunder applicable to the SEC
Reports, and none of the SEC Reports as of such dates contained any untrue
statement of a material fact or omitted to state a material fact required to be
stated therein, in light of the circumstances under which they were made, not
misleading. Except to the extent that any SEC Report has been revised or
superseded by a later filed SEC Report, none of the SEC Reports contains any
untrue statement of a material fact or omits to state any material fact required
to be stated therein or necessary in order to make the statements therein, in
light of the circumstances under which they were made, not misleading. The
consolidated financial statements of the Company included in the SEC Reports
comply as to form in all material respects with applicable accounting
requirements and the published rules and regulations of the Commission with
respect thereto, have been prepared in accordance with generally accepted
accounting principles (except, in the case of unaudited consolidated quarterly
statements, as permitted by Form 10-Q of the Commission) applied on a consistent
basis during the periods involved (except as may be indicated in the notes
thereto) and fairly present in all materials respects the consolidated financial
position of the Company and its consolidated subsidiaries as of the dates
thereof and the consolidated results of their operations and cash flows for the
periods then ended (subject, in the case of unaudited quarterly statements, to
normal year-end audit adjustments).

         (b) The Company owns all the issued and outstanding capital stock or
other equity interests of each of its direct and indirect subsidiaries (the
"Subsidiaries"). Each of the Company and the Subsidiaries is duly incorporated
or organized, validly existing and in good standing as a corporation or a
limited liability company, as the case may be, under the laws of its
jurisdiction of incorporation or organization, with all requisite corporate or
limited liability company power and authority to own or lease its properties and
conduct its business as now conducted, and as proposed to be conducted as
described in the Company's SEC Reports. Except as described on Schedule 2(b)(i),
each of the Company and the Subsidiaries
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                                     - 4 -


is duly qualified to do business as a foreign corporation in good standing in
the jurisdiction in which it has its principal place of business and in all
other jurisdictions where the ownership or leasing of its properties or the
conduct of its business requires such qualification, except where the failure to
be so qualified would not, singly or in the aggregate, have a material adverse
effect on the business, condition (financial or other), assets, nature of
assets, liabilities, operations, prospects or results of operations of the
Company and the Subsidiaries, taken as a whole (any such event, a "Material
Adverse Effect"). Except as described in the SEC Reports, the Company does not
own or control, directly or indirectly, any material interest in any other
corporation, association, or other business entity.

         (c) Except as set forth on Schedule 2(c)(i), the Preferred Stock, the
Warrants, the Conversion Shares, the Warrant Shares, the Change in Control
Warrants (hereinafter defined), any shares of Common Stock issuable upon
exercise of the Change in Control Warrants (the "Additional Warrant Shares"),
and the Certificate of Designation have been duly authorized by the Company. The
Preferred Stock, the Warrants and the Change in Control Warrants, when issued,
sold and delivered in accordance with the terms hereof and for the consideration
expressed herein, and the Warrant Shares, the Additional Warrant Shares and the
Conversion Shares when issued in accordance with the terms of the Warrants, the
Change in Control Warrants and Preferred Stock, as the case may be, (i) will be
duly and validly issued and, in the case of the Preferred Stock, the Warrant
Shares, the Additional Warrant Shares and the Conversion Shares, fully paid and
nonassessable, (ii) will be free of any pledges, liens, security interests,
claims, rights or other encumbrances of any kind (other than under applicable
federal and state securities laws), (iii) assuming the accuracy of the
Purchaser's representations and warranties in this Agreement, will be issued in
compliance with all applicable federal and state securities laws, and (iv) will
not be issued in violation of any preemptive rights of stockholders. Except as
set forth on Schedule 2(c)(ii), the Preferred Stock, the Warrant Shares, the
Additional Warrant Shares and the Conversion Shares have been duly and validly
reserved for issuance.

         (d) The Company has all requisite corporate power and authority to
execute and deliver the Warrant Agreement and the Registration Rights Agreement;
the Warrant Agreement and the Registration Rights Agreement have been duly
authorized by the Company and, when executed and delivered by the Company
(assuming due authorization, execution and delivery by the parties thereto other
than the Company) will constitute valid and legally binding agreements of the
Company, enforceable against the Company in accordance with their terms, except
that (i) the enforcement thereof may be subject to (A) bankruptcy, insolvency,
reorganization, fraudulent conveyance, moratorium or other similar laws now or
hereafter in effect relating to creditors' rights generally, (B) general
principles of equity and the discretion of the court before which any proceeding
therefor may be brought and

<PAGE>   5
                                     - 5 -


(C) any rights to indemnity or contribution thereunder may be limited by federal
and state securities laws and public policy considerations.

         (e) The Company has all requisite corporate power and authority to
execute and deliver this Agreement, the Warrants and the Change in Control
Warrants, to issue the Warrant Shares and the Additional Warrant Shares and,
subsequent to the filing of the Certificate of Designation, to issue and deliver
the Preferred Stock and the Conversion Shares, and to consummate the
transactions contemplated hereby. This Agreement and each other Transaction
Document has been duly authorized, and this Agreement has been and each other
Transaction Document has been or as of the Initial Closing will be duly executed
and delivered by the Company. No consent, approval, authorization or order of
any foreign or domestic national, state, provincial or local government or any
instrumentality, subdivision, court or governmental agency or body thereof, or
any arbitral body (each, a "Governmental Authority") having jurisdiction over
the Company or the Subsidiaries or their respective businesses (including,
without limitation, the Federal Communications Commission (the "FCC")) is
required for the performance of this Agreement and the other Transaction
Documents by the Company or the consummation by the Company of the transactions
contemplated hereby or thereby, except for (x) such consents as have been
obtained, (y) such consents as may be required under state securities or "Blue
Sky" laws in connection with the purchase and resale of the Securities and the
Additional Securities by the Purchaser and (z) any notification as may be
required under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as
amended (the "HSR Act"), or any consent as may be required by the FCC or any
state telecommunications regulatory authorities or commissions ("State
Telecommunications Authorities"), in each such case, as a result of the
Purchaser's conversion of Preferred Stock or exercise of Warrants or Additional
Warrants. Neither the Company nor any of the Subsidiaries nor their operations
is (i) in violation of its certificate of incorporation or by-laws (or similar
organizational document), (ii) in violation of any statute, judgment, decree,
order, rule or regulation applicable to the Company or the Subsidiaries, which
violation would, individually or in the aggregate, be reasonably likely to have
a Material Adverse Effect or (iii) other than as disclosed in the Company's SEC
Reports or as otherwise disclosed in Schedule 2(e), in default in the
performance or observance of any obligation, agreement, covenant or condition
contained in any indenture, mortgage, deed of trust, loan agreement, note,
lease, license, franchise agreement, permit, certificate, contract or other
agreement or instrument to which the Company or the Subsidiaries is a party or
to which the Company or the Subsidiaries or their respective assets is subject,
which default would, individually or in the aggregate, be reasonably likely to
have a Material Adverse Effect.

         (f) Neither the issuance and sale of the Securities or the Change in
Control Warrants and the Additional Securities, nor the execution, delivery and
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                                     - 6 -


performance by the Company of this Agreement, the Warrant Agreement or the
Registration Rights Agreement or the consummation of the transactions
contemplated hereby and thereby, will (i) conflict with the certificate of
incorporation or by-laws of the Company, as the same will be in effect as of
each Closing, (ii) constitute or result in a breach, default or violation of
(with or without the giving of notice, passage of time or both), or result in
the creation or imposition of a lien, charge or encumbrance on any properties or
assets of the Company or the Subsidiaries under any of the terms or provisions
of, any indenture, mortgage, deed of trust, loan agreement, note, lease,
license, franchise agreement, or other agreement or instrument to which the
Company is a party or to which the Company or its respective properties is
subject, (iii) require the consent of any third party or any Governmental
Authorities, and including without limitation as of the Initial Closing, The
NASDAQ Stock Market and any related body ("NASDAQ"), other than (A) required
consents under the Credit Agreement dated as of August 11, 1999 among the
Company, e.spire Finance Corporation, the Lenders, Goldman Sachs Credit Partners
L.P., the Bank of New York, First Union National Bank and Newcourt Commercial
Finance Corporation (the "Credit Agreement"), (B) solely with respect to the
Securities to be issued and sold at the Final Closing, the Stockholder Approval
(hereinafter defined) and (C) any required consents of the FCC or any State
Telecommunications Authority as a result of the Purchaser's conversion of
Preferred Stock or exercise of Warrants; or (iv) (assuming compliance with all
applicable state securities and "Blue Sky" laws, all applicable rules and
regulations of the FCC and State Telecommunications Authorities, and the HSR
Act, and assuming the receipt by the Company of the Stockholder Approval and
assuming the accuracy of the representations and warranties of the Purchaser in
Section 7 hereof) contravene any statute, judgment, decree, order, rule or
regulation of any Governmental Authority applicable to the Company or any of its
respective properties, except for any conflict, breach, violation, default,
lien, charge, contravention or encumbrance referred to in clauses (ii) and (iii)
of this Section 2(f) which would not, individually or in the aggregate, be
reasonably likely to have a Material Adverse Effect. For purposes of this
Agreement, "Stockholder Approval" shall mean the affirmative vote of the holders
of a majority of the shares of the Company's Common Stock present in person or
by proxy at a meeting of stockholders of the Company duly called and held (and
at which meeting a quorum is present) approving the issuance of the Preferred
Stock and Conversion Shares hereunder and to Huff and Greenwich (as each term is
hereinafter defined), as well as the Preferred Stock included in the Subsequent
Securities referred to in Section 13 (and Conversion Shares relating thereto),
as and to the extent all such Preferred Stock and Conversion Shares taken
together may result in the issuance of a number of shares of Common Stock which
exceeds 20% of the total outstanding Common Stock immediately prior to the
Initial Closing. The issuance and sale of the Warrants and the Initial Preferred
Stock (hereinafter defined) at the Initial Closing, any issuance of Change in
Control Warrants, and the issuance of any Additional Securities with respect to
such Initial Preferred Stock and
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                                     - 7 -


Change in Control Warrants pursuant to the conversion or exercise thereof (at an
adjusted conversion or exercise price, as the case may be), without in any case
obtaining Stockholder Approval, is not and at the time of issuance of such
Additional Securities will not be in violation, breach or contravention of any
rule or other requirement or any criteria for listing or continued trading
through NASDAQ (a "NASDAQ Rule") and does not and will not require any consent
of NASDAQ. Subject to obtaining Stockholder Approval, the Remaining Preferred
Stock (hereinafter defined) may be issued and sold at the Final Closing and any
Additional Securities may be issued and sold with respect thereto without
violation, breach or contravention of any NASDAQ Rule and will not require any
consent of NASDAQ.

         (g) Except as described in the Company's SEC Reports, there is neither
pending nor, to the best knowledge of the Company after due inquiry, threatened,
any action, suit, proceeding, inquiry or investigation to which the Company or
any of the Subsidiaries is a party, or to which any of their respective
properties or assets are or would be subject, before or brought by any
Governmental Authority (including, without limitation, the FCC) that would,
individually or in the aggregate, be reasonably likely to have a Material
Adverse Effect or that seeks to restrain, enjoin, prevent the consummation of or
otherwise challenge or relate to the issuance or sale of the Securities or
Additional Securities to be sold hereunder or the consummation of the other
transactions contemplated herein or in the other Transaction Documents.

         (h) Except as disclosed on Schedule 2(h), each of the Company and the
Subsidiaries owns or possesses adequate licenses or other rights to use all
patents, trademarks, service marks, trade names, copyrights and know-how, and as
of each Closing (hereinafter defined) will continue to own or possess such
licenses, rights and know-how and other intellectual property necessary to
conduct the businesses currently operated by it, or as proposed to be conducted
by it as described in the Company's SEC Reports, except for any the absence of
which would not, individually or in the aggregate, be reasonably likely to have
a Material Adverse Effect, and neither the Company nor the Subsidiaries has
received any notice of infringement of, or conflict with (or knows of any such
infringement of or conflict with) asserted rights of others with respect to any
patents, trademarks, service marks, trade names, copyrights or know-how
necessary to conduct the businesses operated by it that, if such assertion of
infringement or conflict were sustained, would, individually or in the
aggregate, have a Material Adverse Effect.

         (i) Each of the Company and the Subsidiaries has obtained, or has
applied for, all consents, approvals, authorizations, orders, registrations,
filings, qualifications, licenses (including, without limitation, all licenses
from the FCC and state, local or other governmental authorities), permits,
franchises and other governmental authorizations necessary to conduct its
businesses (or proposed
<PAGE>   8
                                     - 8 -


businesses) as described in the Company's SEC Reports, except for any the
absence of which, individually or in the aggregate, would not be reasonably
likely to have a Material Adverse Effect. Neither the Company nor any of the
Subsidiaries has received any notice of proceedings related to the revocation or
materially adverse modification of any such consent, approval, authorization,
order, registration, filing, qualification, license or permit, except for any
which would not, individually or in the aggregate, be reasonably likely to have
a Material Adverse Effect.

         (j) Except as disclosed in the SEC Reports, subsequent to September 30,
1999, (i) neither the Company nor any of the Subsidiaries has incurred any
liabilities or obligations, direct or contingent, or entered into any material
transactions not in the ordinary course of business that would, individually or
in the aggregate, be reasonably likely to have a Material Adverse Effect; and
(ii) the Company has not purchased any of its outstanding capital stock or
(except for regularly scheduled pay-in-kind dividends on shares of preferred
stock described under Section 2(r) below) declared, paid or otherwise made any
dividend or distribution of any kind on its capital stock.

         (k) There are no legal or governmental proceedings involving or
affecting the Company or any of the Subsidiaries or any of their respective
properties or assets (other than proceedings, individually or in the aggregate,
which would not, if the subject of an unfavorable decision, ruling or finding,
result in a Material Adverse Effect) that are not described in the SEC Reports.
Except as described in the SEC Reports or Schedule 2(e), neither the Company nor
any of the Subsidiaries is in default under any contract, has received a notice
or claim of any such default or has knowledge of any breach of any such contract
by the other party or parties thereto, except such defaults or breaches which
would not, individually or in the aggregate, be reasonably likely to have a
Material Adverse Effect.

         (l) Each of the Company and the Subsidiaries has filed all necessary
federal, state, local and foreign income, franchise and property tax returns,
except where the failure to so file such returns would not, individually or in
the aggregate, be reasonably likely to have a Material Adverse Effect, and each
of the Company and the Subsidiaries has paid all taxes shown as due when due;
and other than tax deficiencies that the Company or any of the Subsidiaries is
contesting in good faith and for which adequate reserves have been provided,
there is no tax deficiency that has been asserted against the Company or any of
the Subsidiaries that would, individually or in the aggregate, be reasonably
likely to have a Material Adverse Effect. The charges, accruals and reserves on
the consolidated books of the Company in respect of any tax liability for any
years not finally determined are adequate to meet any assessments or
re-assessments for additional tax for any years not finally determined, except
to the extent of any inadequacy that would not,
<PAGE>   9
                                     - 9 -


individually or in the aggregate, be reasonably likely to have a Material
Adverse Effect.

         (m) Except as disclosed in the SEC Reports, each of the Company and the
Subsidiaries has good and marketable title to all real property and good title
to all personal property owned or claimed to be owned by it and good and valid
title to all leasehold interests in the real and personal property leased by it
(except for those leases of real property in which the Company has good title
and that would be marketable but for the requirement that the landlord consent
to an assignment or sublease of the lease), free and clear of all liens,
charges, encumbrances or restrictions, except to the extent the failure to have
such title or the existence of such liens, charges, encumbrances or restrictions
would not, individually or in the aggregate, be reasonably likely to have a
Material Adverse Effect. All leases, contracts and agreements to which the
Company or any of the Subsidiaries is a party or by which any of them is bound
are valid and enforceable against the Company or such Subsidiaries and are valid
and enforceable against the other party or parties thereto and are in full force
and effect with only such exceptions as would not, individually or in the
aggregate, be reasonably likely to have a Material Adverse Effect. No real or
personal property, rights-of-way, conduits, pole attachments or fiber leased,
licensed or used by the Company or any of the Subsidiaries lies in an area that
is, or to the best knowledge of the Company will be, subject to zoning, use, or
building code restrictions that would prohibit, and no state of facts relating
to the actions or inaction of another person or entity or his, her or its
ownership, leasing, licensing or use of any such real or personal property,
rights-of-way, conduits, pole attachments or fiber exists that would prevent the
continued effective leasing, licensing or use of such real or personal property,
rights-of-way, conduits, pole attachments or fiber in the business of the
Company or any of the Subsidiaries as presently conducted, subject in each case
to such exceptions as, individually or in the aggregate, do not have and are not
reasonably likely to have a Material Adverse Effect.

         (n) None of the Company or any of the Subsidiaries is and, after giving
effect to the offering and sale of the Securities and the Additional Securities
and the application of the proceeds therefrom as described herein, none will be,
an "investment company," as such term is defined in the Investment Company Act
of 1940, as amended, and the rules and regulations thereunder.

         (o) Neither the Company nor any of its directors, officers or
controlling persons (provided that Huff is excluded from the warranty in this
Section 2(o)) has taken, directly or indirectly, any action designed, or that
might reasonably be expected, to cause or result, under the Securities Act or
otherwise, in, or that has constituted, stabilization or manipulation of the
price of any security of the Company to facilitate the sale or resale of any of
the Securities or the Additional Securities.
<PAGE>   10
                                     - 10 -


         (p) Each of the Company and the Subsidiaries (i) makes and keeps
accurate books and records and (ii) maintains internal accounting controls that
provide reasonable assurance that (A) transactions are executed in accordance
with management's authorization, (B) transactions are recorded as necessary to
permit preparation of its financial statements and to maintain accountability
for its assets, (C) access to its assets is permitted only in accordance with
management's authorization and (D) the reported accountability for its assets is
compared with existing assets at reasonable intervals.

         (q) None of the Company, any of the Subsidiaries or any of their
respective Affiliates (as defined in Rule 501(b) of Regulation D under the
Securities Act) (provided that Huff is excluded from the warranty in this
Section 2(q)) has directly, or through any agent, (i) sold, offered for sale,
solicited offers to buy or otherwise negotiated in respect of, any "security"
(as defined in the Securities Act) that is or could be integrated with the sale
of the Securities or the Additional Securities in a manner that would require
the registration under the Securities Act of the Securities or the Additional
Securities or (ii) engaged in any form of general solicitation or general
advertising (as those terms are used in Regulation D under the Securities Act)
in connection with the offering of the Securities or the Additional Securities
or in any manner involving a public offering within the meaning of Section 4(2)
of the Securities Act. Assuming the accuracy of the representations and
warranties of the Purchaser in Section 7 hereof, it is not necessary in
connection with the offer, sale and delivery of the Securities or the Additional
Securities to the Purchaser in the manner contemplated by this Agreement to
register any of the Securities or the Additional Securities under the Securities
Act.

         (r) As of the date of this Agreement, the authorized capital of the
Company consists of (i) 125,000,000 shares of Common Stock, of which 51,570,766
shares were issued and outstanding at January 31, 2000 and 43,981,263 are
reserved for issuance and (ii) 3,000,000 shares of preferred stock, par value
$1.00 per share, of which (x) 400,000 shares have been designated 14.75%
Redeemable Preferred Stock due 2008 (the "14.75% Preferred Stock") of which
107,235.94 shares are issued and outstanding, (y) 200,000 shares have been
designated Series A 12.75% Junior Redeemable Preferred Stock due 2009 of which
18.25 shares are issued and outstanding and (z) 700,000 shares have been
designated Series B 12.75% Junior Redeemable Preferred Stock (the "12.75%
Preferred Stock") of which 198,843 shares are issued and outstanding. Except for
(A) 5,968 shares of Common Stock reserved for issuance under the Company's 1996
Employee Stock Purchase Plan; (B) 20,000 shares of Common Stock reserved for
issuance under the Company's 1998 Restricted Stock Plan; (C) 5,646,355 shares of
Common Stock reserved for issuance upon exercise of the warrants issued by the
Company in connection with the sale of the 14.75% Preferred Stock; (D) 2,330,757
shares of Common Stock reserved for issuance upon exercise of the warrants
issued by the
<PAGE>   11
                                     - 11 -


Company in connection with the sale of the Company's 13% Senior Discount Notes
due 2005, (E) 5,500,544 shares of Common Stock reserved for issuance in
connection with the Company's non-plan employee stock options; (F) 3,573,806
shares of Common Stock reserved for issuance under the Company's 1994 Employee
Stock Option Plan; (G) 596,493 shares of Common Stock reserved for issuance
under the Company's Annual Performance Plan; (H) 480,000 shares of Common Stock
reserved for issuance in connection with stock options granted to the Company's
outside directors; (I) 100,000 shares of Common Stock reserved for issuance upon
exercise of warrants issued by the Company in connection with the sale of 12.75%
Preferred Stock; (J) 305,614 shares of Common Stock reserved for issuance upon
exercise of warrants issued by the Company in connection with certain preferred
provider and local services agreements entered into by the Company; (K) 421,726
shares of Common Stock reserved for issuance upon the exercise of warrants
registered pursuant to Form S-3, Commission File No. 333-40337, (L) shares of
Common Stock in an amount up to $600,000 reserved for issuance in connection
with a settlement agreement to be entered into between the Company and a third
party and (M) 29,841,394 shares of Common Stock reserved to be issued in
connection with this Purchase Agreement and the respective purchase agreements,
between Huff and Greenwich and the Company, there are not outstanding (and,
except as contemplated by this Agreement, the Company does not have any plan to
issue, grant or enter into) any options, warrants, rights (including conversion
or preemptive rights), subscriptions or agreements for the purchase, or
acquisition from or by the Company of any shares of its or any of its
Subsidiaries capital stock or any other securities convertible into or
exercisable for any shares of its or any of its Subsidiaries capital stock.
There are no voting agreements, voting trust agreements, stockholder agreements
or other agreements relating to the capital stock of the Company or any of its
Subsidiaries or any other securities convertible into or exercisable for any
shares of its or any of its Subsidiaries capital stock. Except as disclosed in
Schedule 2(r), no outstanding options, warrants or other securities exercisable
for or convertible into Common Stock require anti-dilution adjustments by reason
of the consummation of the transactions contemplated hereby.

         (s) Other than as described in the SEC Reports or in Schedule 2(e),
since September 30,1999 (i) there has not been any change in the capital stock
or long-term indebtedness of the Company or any of the Subsidiaries which could,
individually or in the aggregate, be reasonably expected to have a Material
Adverse Effect and (ii) there has not occurred, nor has information become known
nor has any state of facts arisen that could, individually or in the aggregate,
reasonably be expected to have a Material Adverse Effect whether or not arising
in the ordinary course of business.
<PAGE>   12
                                     - 12 -


         (t) Other than routine individual grievances or disputes in an
individual amount less than $50,000 and in the aggregate less than $250,000,
there is no strike, labor dispute, slowdown or work stoppage with the employees
of the Company or any of the Subsidiaries that is pending or, to the knowledge
of the Company or any of the Subsidiaries, threatened. Neither the Company nor
any Subsidiary is a party to any collective bargaining agreement. The Company
does not know of any activities or proceedings of any labor organization (or
representative thereof) to organize any employees of the Company or any
Subsidiary.

         (u) Each of the Company and the Subsidiaries carries insurance in such
amounts and covering such risks as is adequate for the conduct of its business
and the value of its properties.

         (v) The Company maintains, sponsors, contributes to, or has or has had
an obligation with respect to "employee benefit plans," within the meaning of
Section 3(3) of ERISA, and may or has had obligations with respect to other
bonus, profit sharing, compensation, pension, severance, deferred compensation,
fringe benefit, insurance, welfare, post-retirement, health, life, stock option,
stock purchase, restricted stock, tuition refund, service award, company car,
scholarship, relocation, disability, accident, sick, vacation, holiday,
termination, unemployment, individual employment, consulting, executive
compensation, incentive, commission, payroll practices, retention, change in
control, noncompetition, collective bargaining and other plans, agreements,
policies, trust funds, or arrangements (whether written or unwritten, insured or
self-insured) on behalf of employees, directors, or shareholders of the Company
(whether current, former, or retired) or their beneficiaries (each a "Plan" and,
collectively, the "Plans"). Neither the Company nor any ERISA Affiliate has any
liability, direct or indirect, or actual or contingent (but excluding any
contributions due in the ordinary course) with respect to any plan subject to
Section 412 of the Code, Section 302 of ERISA or Title IV of ERISA that has or
could reasonably be expected to have a Material Adverse Effect. The consummation
of the transactions contemplated by this Agreement will not give rise to any
liability with respect to any Plan that could reasonably be expected to have a
Material Adverse Effect, including, without limitation, liability for severance
pay, unemployment compensation, termination pay or withdrawal liability, or
accelerate the time of payment or vesting or increase the amount of compensation
or benefits due to any employee, director, or shareholder of the Company
(whether current, former, or retired) or their beneficiaries solely by reason of
such transactions. Except as would not individually or in the aggregate have, or
could not reasonably be expected to have, a Material Adverse Effect: (i) neither
the Company nor any ERISA Affiliate has made any promises or commitments to
create any additional plan, agreement, or arrangement; (ii) no event, condition,
or circumstance exists that could result in an increase of the benefits provided
under any Plan or the expense of maintaining any Plan from the level of benefits
or expense incurred for the most recent fiscal year
<PAGE>   13
                                     - 13 -


ended before Closing; and (iii) neither the Company nor any ERISA Affiliate has
or could be expected to have any liability for any prohibited transaction as
defined in Section 406 of ERISA or Section 4975 of the Code. With respect to
each of the Plans: (i) each Plan intended to qualify under Section 401(a) of the
Code has been qualified since its inception and has received a determination
letter under Revenue Procedure 93-39 from the IRS to the effect that the Plan is
qualified under Section 401 of the Code and any trust maintained pursuant
thereto is exempt from federal income taxation under Section 501 of the Code and
nothing has occurred or is expected to occur at or before Closing that caused or
could cause the loss of such qualification or exemption or the imposition of any
penalty or tax liability that has or could reasonably be expected to have a
Material Adverse Effect; (ii) no claim, lawsuit, arbitration, audit or
investigation or other action has been threatened, asserted, instituted, or
anticipated against the Plans (other than non-material routine claims for
benefits, and appeals of such claims), any trustee or fiduciaries thereof, the
Company, any ERISA Affiliate, any director, officer, or employee thereof, or any
of the assets of any trust of the Plans that would have or could reasonably be
expected to have a Material Adverse Effect; (iii) the Plan complies in all
material respects and has been maintained and operated in all material respects
in accordance with its terms and applicable law, including, without limitation,
ERISA and the Code; and (iv) with respect to each Plan that is funded mostly or
partially through an insurance policy, the Company has no liability in the
nature of retroactive rate adjustment, loss sharing arrangement or other actual
or contingent liability arising wholly or partially out of events occurring on
or before Closing that has or could reasonably be expected to have a Material
Adverse Effect.

         (w) Except for matters which would not in the aggregate have a Material
Adverse Effect,

             (i) (A) the Company and each Subsidiary is in compliance with all
         applicable Environmental Laws (as defined below); (B) all permits and
         other authorizations of any Governmental Authority currently held by
         the Company and each Subsidiary pursuant to the Environmental Laws are
         in full force and effect, the Company and each Subsidiary is in
         compliance with all of the terms of such permits and authorizations,
         and no other permits or authorizations are required by the Company or
         any Subsidiary for the conduct of their respective businesses on the
         date hereof; and (C) the management, handling, storage, transportation,
         treatment, and disposal by the Company and each Subsidiary of any
         Hazardous Materials (as defined below) has been in compliance with all
         applicable Environmental Laws. Neither the Company nor any Subsidiary
         has received any written communication that alleges that the Company or
         any Subsidiary is not in compliance in all material respects with all
         applicable Environmental Laws.
<PAGE>   14
                                     - 14 -


             (ii) There is no Environmental Claim (hereinafter defined) pending
         or, to the knowledge of the Company, threatened against or involving
         the Company or any of the Subsidiaries or against any person or entity
         whose liability for any Environmental Claim the Company or any of the
         Subsidiaries has or may have retained or assumed either contractually
         or by operation of law.

             (iii) To the knowledge of the Company, there are no past or present
         actions or activities by the Company or any Subsidiary including the
         storage, treatment, release, emission, discharge, disposal or
         arrangement for disposal of any Hazardous Materials, that could
         reasonably form the basis of any Environmental Claim against the
         Company or any of the Subsidiaries or against any person or entity
         whose liability for any Environmental Claim the Company or any
         Subsidiary may have retained or assumed either contractually or by
         operation of law.

             (iv) As used herein, these terms shall have the following meanings:

                  (A) "Environmental Claim" means any and all administrative,
             regulatory or judicial actions, suits, demands, demand letters,
             directives, claims, liens, investigations, proceedings or notices
             of noncompliance or violation (written or oral) by any person or
             governmental authority alleging potential liability arising out of
             based on or resulting from the presence, or release or threatened
             release into the environment, of any Hazardous Materials at any
             location owned or leased by the Company or any Subsidiary or other
             circumstances forming the basis of any violation or alleged
             violation of any Environmental Law.

                  (B) "Environmental Laws" means all applicable foreign,
             federal, state and local laws (including the common law), rules,
             requirements and regulations relating to pollution, the environment
             (including, without limitation, ambient air, surface water,
             groundwater, land surface or subsurface strata) or protection of
             human health as it relates to the environment including, without
             limitation, laws and regulations relating to releases of Hazardous
             Materials, or otherwise relating to the manufacture, processing,
             distribution, use, treatment, storage, disposal, transport or
             handling of Hazardous Materials or relating to management of
             asbestos in buildings.

                  (C) "Hazardous Materials" means wastes, substances, or
             materials (whether solids, liquids or gases) that are deemed
             hazardous, toxic, pollutants, or contaminants, including without
             limitation,
<PAGE>   15
                                     - 15 -


         substances defined as "hazardous substances", "toxic substances",
         "radioactive materials", or other similar designations in, or otherwise
         subject to regulation under, any Environmental Laws.

         (x) At the Initial Closing, the Company will deliver to the Trustees
under each of the indentures with respect to the Company's Existing Notes (as
such term is defined in the Certificate of Designation): (i) a resolution of the
Company's Board of Directors certifying that (A) the transactions contemplated
by this Agreement and the other Transaction Documents are on terms no less
favorable to the Company than those that would have been obtained in a
comparable arms-length transaction by the Company with a person or entity that
is not an Affiliate (as such term is defined in the respective Indentures), and
(B) the transactions contemplated by this Agreement have been unanimously
approved by the Independent Directors (as such term is defined in the respective
Indentures) on the Company's Board of Directors, who have determined that such
transactions are in the best interests of the Company, (ii) opinions of Houlihan
Lokey Howard & Zukin that such transactions are fair to the Company from a
financial point of view, and (iii) copies of the officers' certificates
delivered to the Trustees to the effect that such opinions comply with the
Indentures, all of the foregoing in conformity with the requirements of the
Indentures. None of such resolutions, opinions or certificates has been
withdrawn or modified in any material respect.

         (y) Except for (i) commitment fees paid to the Purchaser and to Huff
and Honeywell, if any, and (ii) payment of commissions to Marvin Saffian
pursuant to the terms of the Consulting Agreement, dated October 19, 1994,
between Marvin Saffian and the Company (which is the Company's obligation), no
broker, finder or investment banker is entitled to any brokerage, finder's or
other fee or commission in connection with the transactions contemplated by this
Agreement or the other Transaction Documents based upon arrangement made by or
on behalf of the Company.

         Any certificate signed by any officer of the Company or any Subsidiary
and delivered to the Purchaser or to counsel for the Purchaser shall be deemed a
representation and warranty by the Company and each of its Subsidiaries to the
Purchaser as to the matters covered thereby.

         No representation or warranty of the Company contained herein shall be
affected by any knowledge of or attributable to any employee or other
representative of the Purchaser including without limitation any present or
former representative on or observer to the Company's or its Subsidiaries'
boards of directors who is an employee, designee, or affiliate of the Purchaser.

             2A. Representations and Warranties of the Purchaser.
<PAGE>   16
                                     - 16 -


         The Purchaser represents and warrants to and agrees with the Company
that the source of funds (the "Source") to be used by the Purchaser to pay the
purchase price of the Securities to be purchased by the Purchaser hereunder is
one or more employee benefit plans, or a separate account or trust fund
comprised of one or more employee benefit plans, each of which has been
identified to the Company in writing. As used in this Section, the term
"employee benefit plan", has the meaning assigned to such term in Section 3 of
ERISA.

             3. Purchase, Sale and Delivery of the Securities.

         (a) Subject to the terms and conditions of this Agreement, (i) at the
Initial Closing, subject to possible reduction in the number of Securities to be
purchased by the Purchaser at the Initial Closing in accordance with Section
3(d) below, the Purchaser shall purchase and the Company shall sell and issue to
the Purchaser (A) all of the Warrants and (B) that number of shares of Preferred
Stock (the "Initial Preferred Stock") as would result (if the shares of
Preferred Stock included in the Initial Preferred Stock were then converted) in
the issuance of shares of Common Stock equal to 19.9% of the shares of Common
Stock of the Company outstanding immediately prior to the Initial Closing and
(ii) at the Final Closing (hereinafter defined) the Purchaser shall purchase and
the Company shall sell and issue to the Purchaser that number of shares of
Preferred Stock (the "Remaining Preferred Stock") equal to the difference
between (x) 100,000 and (y) the number of shares of Initial Preferred Stock sold
and issued to the Purchaser at the Initial Closing. The Company shall deliver to
the Purchaser at the Initial Closing a schedule, certified by the Company's
Chief Financial Officer, setting forth in such reasonable detail as may be
requested by the Purchaser, the calculations called for by this Section 3(a).

         (b) The purchase and sale of the Warrants and the Initial Preferred
Stock shall take place at the offices of Proskauer Rose LLP, 1585 Broadway, New
York, New York 10036, within two (2) days following the satisfaction of the
conditions set forth in this Agreement required to be satisfied prior to the
consummation of the purchase and sale of the Warrants and the Initial Preferred
Stock hereunder, but in no event later than March 6, 2000, or at such other time
and place as the Company and the Purchaser mutually agree upon in writing (which
time and place are designated as the "Initial Closing"). At the Initial Closing,
the Company shall deliver to the Purchaser one or more certificates representing
the Initial Preferred Stock being sold and issued, and an executed Warrant
representing all of the Warrants, in such denomination or denominations and
registered in such name or names as the Purchaser shall request upon notice to
the Company against payment by or on behalf of the Purchaser of the purchase
price therefor by wire transfer, payable to or upon the order of the Company in
immediately available funds.
<PAGE>   17
                                     - 17 -


         (c) The purchase and sale of the Remaining Preferred Stock shall take
place at the offices of Proskauer Rose LLP, 1585 Broadway, New York, New York
10036, within two (2) days following the satisfaction of the conditions set
forth in this Agreement required to be satisfied prior to consummation of the
purchase and sale of the Remaining Preferred Stock, but in no event later than
100 days following the Initial Closing, or at such other time and place as the
Company and the Purchaser mutually agree upon orally or in writing (which time
and place are designated as the "Final Closing"). At the Final Closing, the
Company shall deliver to the Purchaser one or more certificates representing the
Remaining Preferred Stock being sold and issued, in such denomination or
denominations and registered in such name or names as the Purchaser shall
request upon notice to the Company, against payment by or on behalf of the
Purchaser of the purchase price therefor by wire transfer, payable to or upon
the order of the Company in immediately available funds.

         (d) In the event that Greenwich Street Capital Partners II, L.P. or any
affiliate fund thereof ("Greenwich") and The Huff Alternative Income Fund, L.P.
("Huff"), agree to purchase Securities at the Initial Closing, then (i) the full
number of Warrants provided under Section 3(a)(i) above to be issued and sold by
the Company to the Purchaser at the Initial Closing shall be issued and sold to
the Purchaser at the Initial Closing; and (ii) the number of shares of Initial
Preferred Stock provided under Section 3(a)(i) above to be issued and sold by
the Company to the Purchaser at the Initial Closing shall be allocated 28.57143%
to the Purchaser, 14.28572% to Greenwich and 57.14285% to Huff.

         (e) Notwithstanding anything to the contrary elsewhere in this
Agreement, in the event that the per share closing price of the Common Stock on
the day immediately preceding the Initial Closing is less than $6.27, then (A)
notwithstanding anything to the contrary contained herein (including without
limitation Section 6(c)(i) below), no Stockholder Approval shall be required in
connection with the transactions contemplated by this Agreement and (B) the
Final Closing shall occur as soon as reasonably practicable after the Initial
Closing.

         The Initial Closing and the Final Closing are sometimes referred to
collectively in this Agreement as the "Closings" and each as a "Closing".

             4. Covenants of the Company. The Company covenants and agrees with
the Purchaser (and in the case of the last sentence of Section 4(f), the
Purchaser agrees) that:

         (a) The Company will cooperate at its expense with the Purchaser in
arranging for the qualification of the Securities and the Additional Securities
for offering and sale under the securities or "Blue Sky" laws of such
jurisdictions as the Purchaser may designate and will continue such U.S.
qualifications in effect for as
<PAGE>   18
                                     - 18 -


long as may be necessary to complete the resale of the Securities and the
Additional Securities by the Purchaser; provided, however, that in connection
therewith the Company shall not be required to qualify as a foreign corporation
or to execute a general consent to service of process in any jurisdiction or
subject the Company to any tax in any such jurisdiction where it is not then so
subject. The Company will cooperate with the Purchaser to (i) if requested,
permit the Warrants and the Change in Control Warrants, to the extent eligible
for resale pursuant to Rule 144A, to be designated PORTAL securities in
accordance with the rules and regulations adopted by the NASD relating to
trading in the Private Offerings, Resales and Trading through Automated Linkages
Market (the "PORTAL Market"), (ii) if requested, permit the Securities upon
issuance and registration under the Securities Act to be eligible for clearance
and settlement through The Depository Trust Company and (iii) permit the
Additional Securities upon issuance and registration under the Securities Act to
be listed for quotation through the Nasdaq National Market or listed on any
national securities exchange on which the Company's Common Stock is then listed.

         (b) Approximately two-thirds of the aggregate net proceeds from the
issuance and sale of the Units will be used by the Company for general corporate
purposes; the remaining one-third of the aggregate net proceeds will be
contributed by the Company to its subsidiary, ACSI Network Technologies, Inc.,
for its general corporate purposes.

         (c) From time to time, and as soon as reasonably practicable upon
demand, the Company will provide to the Purchaser such additional information
regarding results of operations, financial condition, business or prospects of
the Company or the Subsidiaries, including without limitation, cash flow
analyses, financial statements, budgets, business plans, projections and other
financial information and minutes of any meetings of the Board of Directors of
the Company or the Subsidiaries, as may be reasonably requested by the
Purchaser. The Company shall also afford to the Purchaser (and its
representatives) access, at reasonable times and on reasonable prior notice, to
the books, records and properties of the Company and the Subsidiaries, and shall
permit the Purchaser (and its representatives) to make copies of such books and
records and also shall afford such access to meet and consult with management
and the advisors of the Company and its Subsidiaries with respect to the
business of the Company and its Subsidiaries.

         (d) Neither the Company nor any of its Affiliates (provided that the
Purchaser shall be excluded from the Company's obligations under this Section
4(d)) will sell, offer for sale or solicit offers to buy or otherwise negotiate
in respect of any "security" (as defined in the Securities Act) that could be
integrated with the sale of the Securities or the Additional Securities in a
manner that would require the registration under the Securities Act of the
Securities or the Additional Securities.
<PAGE>   19
                                     - 19 -


         (e) The Company will not, and will not permit any of the Subsidiaries
to, engage in any form of general solicitation or general advertising (as those
terms are used in Regulation D under the Securities Act) in connection with the
offering of the Securities or the Additional Securities or in any manner
involving a public offering within the meaning of Section 4(2) of the Securities
Act.

         (f) The Company will take all action necessary in accordance with
applicable law and its Certificate of Incorporation and By-laws to convene a
special meeting of its stockholders as promptly as practicable to obtain the
Stockholder Approval. The Board of Directors of the Company shall, subject to
its fiduciary duties, recommend such approval to the stockholders of the Company
and the Company shall take all lawful actions and use its best efforts to
solicit and obtain such approval. The Company and the Purchaser hereby
acknowledge and agree that neither any Conversion Shares nor any Warrant Shares
may be voted at such meeting or otherwise to obtain Stockholder Approval.

         (g) As soon as practicable (but not later than March 7, 2000), the
Company shall file a proxy statement in preliminary form with the Commission in
connection with the special meeting of the Company's stockholders to consider
and vote upon the Stockholder Approval. Such proxy statement (or the proxy
statement for the next annual meeting of stockholders) shall include a proposal
seeking stockholder approval of an increase in the authorized Common Stock of
the Company for the reservation for issuance of a sufficient number of shares of
Common Stock issuable upon conversion, exercise or payment of dividends with
respect to the Securities. The Company shall make the drafts of the proxy
statement available to the Purchaser for its review reasonably in advance of
filing. The Purchaser agrees to reasonably cooperate with the Company in the
preparation of the proxy statement. The definitive proxy statement ("Proxy
Statement") for the stockholders meeting shall be mailed to stockholders as soon
as practicable. The Company shall cause the Proxy Statement to comply in all
material respects with the requirements of the Exchange Act, and the applicable
rules and regulations thereunder, and to contain no untrue statement of any
material fact or omit to state any material fact required to be stated therein
or necessary to make the statements therein, in light of the circumstances in
which they were made, not misleading.

         (h) At all times prior to the earlier to occur of the Final Closing or
termination of this Agreement (including any termination of this Agreement with
respect to the Remaining Preferred Stock) pursuant to Section 10(a)(iv)), the
Company will amend or supplement each SEC Report to the extent required to
correct any untrue statement of a material fact contained therein or any
omission of a material fact required to be stated therein to make the statements
in such SEC Report, in light of the circumstances under which they were made,
not misleading. From and after the date of this Agreement and at all times prior
to the earlier to occur
<PAGE>   20
                                     - 20 -


of the Final Closing or termination of this Agreement (including any termination
of this Agreement with respect to the Remaining Preferred Stock pursuant to
10(a)(iv)), the Company shall timely file with the Commission true, accurate and
complete copies of all reports, schedules, forms, statements and other documents
required to be filed by the Company ("Required Filings"). All of such Required
Filings shall comply in all material respects with the requirements of the
Securities Act, or the Exchange Act, as the case may be, and the rules and
regulations of the Commission promulgated thereunder applicable to the Required
Filings.

         (i) The Company hereby covenants and agrees that, prior to the earlier
to occur of the Final Closing or the termination of this Agreement, unless
otherwise expressly contemplated by this Agreement or consented to beforehand in
writing by Huff, the Company shall, and shall cause each Subsidiary to, operate
its business only in the usual and ordinary course consistent with past
practices.

         (j) The Company hereby covenants and agrees that, prior to the Initial
Closing it shall file or cause to be filed with the Secretary of State of
Delaware the Certificate of Designation.

         (k) The Company hereby covenants and agrees that, prior to the earlier
to occur of the Final Closing or termination of this Agreement, unless consented
to in writing beforehand by Huff, and except for pay-in-kind dividends in
respect of the 14.75% Preferred Stock and the 12.75% Preferred Stock, the
Company will not issue or take any action to issue any capital stock or
securities convertible into or exercisable for any capital stock having rights,
privileges or preferences, including, without limitation, with respect to the
payment of dividends or payment upon liquidation of the Company (bankruptcy or
otherwise), that are on a par or senior to any payment on the Preferred Stock in
any respect, or that are redeemable for cash, or that provide for the payment of
dividends in cash ahead of any payment on the Preferred Stock, whether at the
option or right of the holder or the Company or its affiliates, unless expressly
consented to beforehand in writing by the Purchaser.

         (l) The Company shall timely file any and all statements or reports
required to be filed by it with the Commission under and in accordance with the
Securities Act and the Exchange Act.

         (m) As soon as practicable after the Purchaser's request therefor, the
Company shall (at its sole expense) file any notices, requests, registrations or
approvals required to be filed with the Federal Communications Commission or any
applicable state regulatory agency or commission in connection with the sale of
the Securities and the Additional Securities under the Purchase Agreements and
the sale of any Subsequent Securities and shall use its reasonable best efforts
to cause such
<PAGE>   21
                                     - 21 -


notices, requests, registrations or approvals to be processed successfully or
approved, as the case may be.

         (n) As soon as practicable after the Purchaser's request therefor, the
Company shall (at its sole expense) file any notifications under the HSR Act as
may be required as a result of the conversion or exercise of the Securities and
shall use its reasonable best efforts and shall cooperate with Purchaser to
cause the early termination or expiration of the waiting period for any such
notifications.

         (o) The Company shall comply with all of its obligations in respect of
the MCI Preemptive Right.

             5. Expenses. The Company agrees to pay the following costs and
expenses and all other costs and expenses incident to the performance of its
obligations under this Agreement and the other Transaction Documents, whether or
not the transactions contemplated herein or therein are consummated or this
Agreement is terminated pursuant to Section 10 hereof: (i) the preparation
(including printing), issuance and delivery to the Purchaser of certificates
evidencing the Securities and the Additional Securities, including transfer
agent's fees, (ii) the qualification of the Securities and the Additional
Securities under state securities and "Blue Sky" laws, including filing fees and
reasonable fees and disbursements of counsel relating thereto, (iii) the fees
and expenses of the transfer agent and registrar of the Company, including fees
and expenses of its counsel, (iv) any fees and expenses incurred by the
Purchaser in connection with any filing required to be made pursuant to the HSR
Act, including filing fees and reasonable fees and disbursements of their
respective counsel whenever such filings are made, (v) Purchaser's appraisal
costs not to exceed $10,000 annually, (vi) all expenses and listing fees
incurred in connection with the application, if requested, for quotation of the
Warrants and the Change of Control Warrants on the PORTAL Market, to the extent
eligible for resale under Rule 144A, and (vii) all other ongoing costs of
holding or converting or exercising the Securities, but excluding ordinary
custodial expenses, brokerage and/or underwriting commissions and taxes.

             6. Conditions of the Obligations of the Purchaser.

         (a) Conditions to the Purchaser's Obligations at Each Closing.

         The obligations of the Purchaser with respect to each Closing under
this Agreement are subject to the fulfillment at or before each Closing of each
of the following conditions:

             (i) The Purchaser shall have received opinions, dated as of each
         Closing, of (i) the opinion of Riley M. Murphy, Esq., General Counsel
         for the
<PAGE>   22
                                     - 22 -


         Company; (ii) the opinion of Kelly Drye & Warren LLP, special
         regulatory counsel for the Company, and (iii) the opinion of Davis Polk
         & Wardwell, special counsel for the Company, all in form and substance
         consistent with the Company's opinions in prior private placements as
         may be reasonably agreed upon by the parties.

             (ii) The representations and warranties of the Company contained in
         this Agreement shall be true and correct when made and true and correct
         at each Closing as if made on and as of each Closing (other than to the
         extent any such representation or warranty is expressly made as to a
         certain date); the Company shall have performed all covenants and
         agreements in all material respects and satisfied all conditions on its
         part to be performed or satisfied hereunder at or prior to the Closing;
         and subsequent to September 30, 1999 no event shall have occurred which
         has had, or in the judgment of the Purchaser, is reasonably likely to
         have a Material Adverse Effect, other than as described in the SEC
         Reports or as disclosed in Schedule 2(e).

             (iii) The issuance and sale of the Securities and Change in Control
         Warrants pursuant to this Agreement shall not be enjoined (temporarily
         or permanently) and no restraining order or other injunctive order
         shall have been issued or any action, suit or proceeding shall have
         been commenced with respect to this Agreement or other Transaction
         Document before any court or Governmental Authority (including, without
         limitation, the FCC).

             (iv) The Purchaser shall have received certificates, dated as of
         each Closing, signed on behalf of the Company by its Chief Operating
         Officer and its Chief Financial Officer to the effect that:

                  (A) The representations and warranties of the Company in this
             Agreement were true and correct when made and true and correct at
             each Closing as if made on and as of each Closing (other than to
             the extent any such representation or warranty is expressly made as
             to a certain date), and the Company has performed all covenants and
             agreements in all material respects and satisfied all conditions on
             its part to be performed or satisfied hereunder at or prior to the
             Closing;

                  (B) Subsequent to September 30, 1999, no event has occurred
             that has had, or is reasonably likely to have, a Material Adverse
             Effect, other than as described in the SEC Reports or as disclosed
             in Schedule 2(e);
<PAGE>   23
                                     - 23 -


                  (C) The issuance and sale of the Securities and the Change in
             Control Warrants hereunder by the Company has not been enjoined
             (temporarily or permanently);

                  (D) As at December 31, 1999 (and after giving effect to all
             financial results, events and other circumstances through the close
             of business on such date), the Company and e.spire Finance
             Corporation were in compliance with each of the covenants and
             obligations of the Company and e.spire Finance Corporation set
             forth in Sections 6.5 and 6.6 of the Credit Agreement.

             (v) All authorizations, approvals or permits, if any, of any
         Governmental Authority that are required in connection with the lawful
         issuance and sale of the Securities or the Change in Control Warrants
         pursuant to this Agreement or (subject to the matters set forth in
         Section 2 (e) and (z) above) the Additional Securities pursuant to the
         terms thereof shall have been duly obtained.

             (vi) Other than the Stockholder Approval in the case of the Final
         Closing and other than any notification under the HSR Act and any
         consent of the FCC or any State Telecommunications Authority that may
         be required as a result of the conversion or exercise of the
         Securities, all consents and waivers, if any, of third parties that are
         required in connection with such Closing under this Agreement and the
         consummation of the transactions contemplated hereby, shall be duly
         obtained and effective as of the Closing.

             (vii) All corporate and other proceedings required in connection
         with the transactions contemplated at such Closing and all documents
         incident thereto shall be satisfactory in form and substance to the
         Purchaser and its counsel and the Purchaser and such counsel shall have
         received such counterpart originals and certified or other copies of
         such documents as they may reasonably request.

             (viii) On or before the Closing Date, the Purchaser (and its
         counsel) shall have received such further documents, certificates and
         schedules or instruments relating to the business, corporate, legal and
         financial affairs of the Company as they shall have heretofore
         reasonably requested from the Company.

             (ix) The Company and the Purchaser shall have entered into the
         Registration Rights Agreement and the Warrant Agreement.
<PAGE>   24
                                     - 24 -


             (x) The Company shall have received the written confirmation of
         NASDAQ, in form and substance satisfactory to the Purchaser and its
         counsel, that other than obtaining Stockholder Approval as contemplated
         by Section 2(f) above, the Securities, Additional Securities and Change
         in Control Warrants may be issued and sold, and the transactions
         contemplated by this Agreement and the other Transaction Documents may
         be consummated, without breach, violation or contravention of any
         NASDAQ Rule ("NASDAQ Approval").

             (xi) The Company shall have filed the Certificate of Designation
         with the Secretary of State of Delaware and the same shall have become
         effective and be in full force and effect.

             (xii) Since January 18, 2000, there shall not have been any
         material adverse change in the price of the Common Stock.

             (xiii) As at December 31, 1999 (and after giving effect to all
         financial results, events and other circumstances through the close of
         business on such date), the Company and e.spire Finance Corporation
         were in compliance with each of the covenants and obligations of the
         Company and e.spire Finance Corporation set forth in Sections 6.5 and
         6.6 of the Credit Agreement.

             (xiv) Either the Purchaser shall have received confirmation from
         the Company's independent certified public accountants reasonably
         satisfactory to the Purchaser that no "going concern" or similar
         exception will be taken in connection with the Company's financial
         statements for the year ended December 31, 1999, or the Purchaser shall
         have received a waiver reasonably acceptable to it from the lenders
         under the Credit Agreement of any default under the Credit Agreement
         relating to such "going concern" or similar exception, provided, that
         if Huff waives the Company's compliance with Section 6(a)(xiv) of the
         purchase agreement between the Company and Huff dated as of the date
         hereof, such waiver shall be deemed a waiver by the Purchaser of the
         Company's compliance under this Section 6(a)(xiv).

         (b) Additional Conditions to the Purchaser's Obligation at the Initial
Closing.

             In addition to the conditions set forth in Section 6(a) above, the
obligations of the Purchaser to the Company under this Agreement are subject to
the fulfillment on or before the Initial Closing of the following additional
conditions:

             (i) Approval of Budget. The Company shall have prepared and
         submitted to Huff its final budget for the fiscal year ended December
         31, 2000
<PAGE>   25
                                     - 25 -


         and Huff shall have approved such budget (together with any updates or
         revisions thereof) or shall have waived in writing such approval.

             (ii) Issuance of Warrants. The Warrants (and if a Change in Control
         shall have occurred, the Change in Control Warrants) shall have been
         issued at the Initial Closing.

             (iii) Issuance of Stock Certificates. The certificates representing
         the shares of Initial Preferred Stock shall have been executed and
         delivered by the Company to the Purchaser at the Initial Closing.

         (c) Additional Conditions to the Purchaser's Obligations at the Final
Closing

             In addition to the conditions set forth in Section 6(a) above, the
obligations of the Purchaser to the Company under this Agreement are subject to
the fulfillment on or before the Final Closing of the following additional
conditions:

             (i) Stockholder Approval. The Company shall have obtained the
         Stockholder Approval or it shall have been determined that such
         approval is not required as provided in Section 3(e).

             (ii) Issuance of any Change in Control Warrants. If a Change in
         Control shall have occurred, the Change in Control Warrants shall have
         been issued.

             (iii) Issuance of Stock Certificates. The certificates representing
         the Remaining Preferred Stock shall have been executed and delivered by
         the Company to the Purchaser at the Final Closing.

         (d) Failure of Certain Conditions To Be Met.

             (i) If on the trading day immediately preceding the Initial Closing
         the closing price of the Common Stock as reported in the New York
         edition of the Wall Street Journal is less than $6.26145 per share
         (subject to appropriate adjustment for stock dividends, stock splits
         and similar events) (a "Stock Decline"), then in such event the
         exercise price of all Warrants (including, without limitation, the
         Change in Control Warrants) shall be reset to equal $7.25 per share
         (subject to adjustment in accordance with the provisions of the Warrant
         Agreement in connection with events other than the Stock Decline).

             (ii) In the event that there shall be a Change in Control of the
         Company, then the Purchaser shall receive simultaneously with the
<PAGE>   26
                                     - 26 -


         occurrence of the Change in Control or as soon thereafter as shall be
         practicable 12,500 additional Warrants (the "Change in Control
         Warrants"), each of which Change in Control Warrants being exercisable
         for the same number of shares of Common Stock and at the same exercise
         price as are than in effect under the Warrants (or, if no Warrants are
         then outstanding, as would have been in effect had Warrants then been
         outstanding) and otherwise having the same terms and subject to the
         same conditions as the Warrants. As used herein, the term "Change in
         Control" means (A) the sale, conveyance, transfer or lease of all or
         substantially all of the assets of the Company (which, for purposes of
         this sentence, shall include any successor to the Company) to any
         "person" or "group" (within the meaning of Section 13(d)(3) and
         14(d)(2) of the Exchange Act or any successor provision to either of
         the foregoing, including any group acting for the purpose of acquiring,
         holding or disposing of securities within the meaning of Rule
         13d-5(b)(i) under the Exchange Act), other than to the Purchaser, ING
         Equity Partners L.P.I., Apex Investment Fund I, L.P., Apex Investment
         Fund II, L.P., The Productivity Fund II, L.P. and Anthony Pompliano
         (including any affiliate of any of the foregoing other than the Company
         or any Restricted Subsidiary of the Company (as defined in the
         Indenture, dated July 24, 1998 with respect to the Company's 10.625%
         Senior Discount Notes Due July 1, 2008)) (the "Permitted Holders")
         shall have occurred; or (B) any "person" or "group" (within the meaning
         of Sections 13(d)(3) and 14(d)(2) of the Exchange Act or any successor
         provision to either of the foregoing, including any group acting for
         the purpose of acquiring, holding or disposing of securities within the
         meaning of Rule 13d-5(b)(i) under the Exchange Act), other than any
         Permitted Holder, becomes the "beneficial owner" (as defined under the
         Exchange Act) of more than 35 percent of the total voting power of all
         classes of the voting capital stock of the Company (including any
         warrants, options or rights to acquire such voting capital stock),
         calculated on fully diluted basis, and such voting power percentage is
         greater than or equal to the total voting power percentage then
         beneficially owned by the Permitted Holders in the aggregate; or (C)
         during any period of two consecutive years, individuals who at the
         beginning of such period constituted the Board of Directors of the
         Company (together with any new directors whose election or appointment
         by such board or whose nomination for election by the stockholders of
         the Company was approved by a vote a majority of the directors then
         still in office who were either directors at the beginning of such
         period or whose election or nomination for election was previously so
         approved) cease for any reason to constitute a majority of the Board of
         Directors then in office. Notwithstanding anything to the contrary
         herein or in any other Transaction Document, the parties hereby agree
         that the provisions of this Section 6(e) (and any other provisions
         hereof or any other Transaction Document relating to the Change in
         Control Warrants or any Additional Securities issuable in connection
         therewith)
<PAGE>   27
                                     - 27 -


         may be amended by the Company and the holders of a majority of the
         outstanding shares of Preferred Stock (including any shares of
         Preferred Stock issued to Purchaser hereunder, to Greenwich, to Huff
         and to any Additional Purchasers (hereinafter defined) (the "Majority
         Holders"), and any waiver relating to such change in Control Warrants
         and/or Additional Securities may be given on behalf of the Purchaser by
         such Majority Holders; provided, however, that any such amendment or
         waiver treats all holders of Preferred Stock in the same fashion.

             7. Restrictions on Transfer. The Purchaser hereby represents and
warrants to the Company that:

         (a) The Securities to be purchased by the Purchaser will be acquired
for investment for its own account, and, except as contemplated by the Warrant
Agreement and the Registration Rights Agreement or otherwise in accordance with
applicable securities laws, not with a view to the resale or distribution of any
part thereof and without the present intention of selling, granting any
participation in, or otherwise distributing the same.

         (b) The Purchaser is an "accredited investor" within the meaning of
Rule 501(a) under the Securities Act and can bear the economic risk of its
investment and has such knowledge and experience in financial or business
matters that it is capable of evaluating the merits and risks of the investment
in the Securities and has received all information from the Company that it has
requested with respect to the Company and the Securities.

         (c) The Purchaser understands that the Securities it is purchasing are
characterized as "restricted securities" under the federal securities laws
inasmuch as they are being acquired from the Company in a transaction not
involving a public offering and that under such laws and applicable regulations
such securities may be resold without registration under the Securities Act,
only in certain limited circumstances. In this connection, the Purchaser
represents that it is familiar with Rule 144 of the Commission, as presently in
effect, and understands the resale limitations imposed hereby by the Securities
Act.

         (d) The Purchaser understands that the certificates evidencing the
Securities will bear a legend evidencing the foregoing restrictions on transfer.

         The Securities shall not be required to bear a restrictive legend if a
registration statement under the Securities Act is effective with respect to the
transfer of such securities or an opinion of counsel reasonably satisfactory to
the Company is delivered to the Company to the effect that neither the legend
nor the restrictions on transfer described in this Agreement are required to
ensure compliance with the
<PAGE>   28
                                     - 28 -


Securities Act. Whenever, pursuant to the preceding sentence, any certificate
for any of the Securities is no longer required to bear a restrictive legend,
the Company may and if requested by the holder thereof, shall, issue to the
holder, at the Company's expense any new certificate not bearing a restrictive
legend.

             8. Indemnification. (a) The Company agrees to indemnify the
Purchaser, each of its affiliates and each officer, director, employee, member,
partner (whether general or limited) and agent of the Purchaser and of each of
its affiliates (the "Indemnified Parties") for, and to hold each Indemnified
Party harmless from and against any and all damages, losses, claims and other
liabilities of any and every kind, including, without limitation, judgments and
costs of settlement (or actions or other proceedings commenced or threatened in
respect thereof) and reasonable expenses that arise out of, result from or in
any way relate to this Agreement or any other Transaction Document, or in
connection with any of the transactions contemplated hereby or thereby,
including, without limitation, in connection with the preparation, filing with
the Commission and mailing to the Company's stockholders of the proxy statement
for the Stockholder Approval and any other proxy statement for the increase in
the authorized Common Stock referred to in Section 4(g) (other than ordinary
investment losses to the extent not arising in connection with (A) any actual or
alleged misrepresentation or breach of covenant, warranty duty or obligation by
the Company or (B) any actual or threatened action or proceeding arising out of,
resulting from or in any way relating to this Agreement or any other Transaction
Document, or any of the transactions contemplated hereby or thereby), and to
reimburse each Indemnified Party, upon its demand, for any reasonable legal or
other expenses incurred in connection with investigating, defending or
participating in any such loss, claim, damage, liability or action or other
proceeding (whether or not such person is a party to any action or proceeding
out of which such expenses arise). The Indemnified Parties shall have the right
to select counsel, subject to the prior consent of the Company, which consent
shall not be unreasonably withheld or delayed, to defend the Indemnified Parties
at the Company's expense in any action or proceeding that is the subject of
indemnification hereunder, provided, that the Company shall not be liable for
the fees and expenses of more than one counsel (plus any local counsel) for all
Indemnified Parties (unless any Indemnified Party shall have reasonably
determined that an actual or potential conflict of interest makes such common
representation inappropriate) in connection with any such action or proceeding.
The Company will not be required to indemnify any Indemnified Party for any
amount paid in settlement of any action or proceeding which is the subject of
indemnification hereunder unless the Company shall have consented in writing to
such settlement, such consent not to be unreasonably withheld or delayed. The
Company shall not, without the prior consent of the Indemnified Party, effect
any settlement or compromise of any pending or threatened proceeding in respect
of which any Indemnified Party is or could have been a party, or indemnity could
have been sought hereunder by such Indemnified Party, unless such settlement (A)
<PAGE>   29
                                     - 29 -


includes an unconditional written release of such Indemnified Party, in form and
substance reasonably satisfactory to such Indemnified Party, from all liability
on claims that are the subject matter of such proceeding and (B) does not
include any statement as to an admission of fault, culpability or failure to act
by or on behalf of any Indemnified Party.

         (b) If the indemnification provided for in Section 8(a) above is for
any reason unavailable to, or insufficient to hold harmless, an Indemnified
Party in respect of any losses, claims, damages or liabilities referred to
therein, then the Company, in lieu of indemnifying such Indemnified Party
thereunder and in order to provide for just and equitable contribution, shall
contribute to the amount paid or payable by such Indemnified Party as a result
of such losses, claims, damages or liabilities in such proportion as is
appropriate to reflect (i) the relative benefits received by the Indemnified
Party or Parties on the one hand and the Company on the other from the offering
of the Units or the Change in Control Warrants or (ii) if the allocation
provided by the foregoing clause (i) is not permitted by applicable law, not
only such relative benefits but also the relative fault of the Company on the
one hand and the Indemnified Party or Parties on the other in connection with
any statements or omissions or alleged statements or omissions or other matters
that resulted in such losses, claims, damages or liabilities (or actions in
respect thereof) as well as any other relevant equitable considerations. The
relative fault of the parties shall be determined by reference to, among other
things, whether any untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the Company on the one hand or such Indemnified Party, on the other,
the parties' relative intent, knowledge, access to information and opportunity
to correct or prevent such statement or omission, and any other equitable
considerations appropriate in the circumstances.

         (c) The parties agree that it would not be just and equitable if
contribution pursuant to this Section 8 were determined by pro rata allocation
(even if the Indemnified Parties were treated as one entity for such purpose) or
by any other method of allocation that does not take account of the equitable
considerations referred to in Section 8(b) above. The amount paid or payable by
the Company as a result of the losses, claims, damages and liabilities referred
to in Section 8(b) above shall be deemed to include, subject to the limitations
set forth above, any reasonable legal or other expenses actually incurred by
such Indemnified Party in connection with investigating or defending any such
action or claim.

             9. Survival Clause. The respective representations, warranties,
agreements, covenants, indemnities and other statements of the Company or its
officers and of the Purchaser set forth in this Agreement or made by or on
behalf of them, respectively, pursuant to this Agreement shall remain in full
force and effect, regardless of (i) any investigation made by or on behalf of
the Company or the
<PAGE>   30
                                     - 30 -


Purchaser and (ii) delivery of and payment for the Securities. The respective
agreements, covenants, indemnities and other statements set forth in Sections 5
and 8 hereof shall remain in full force and effect, regardless of any
termination or cancellation of this Agreement.

             10. Termination.

         (a) This Agreement may be terminated prior to the Initial Closing or
the Final Closing, as the case may be, under the following circumstances and by
the following persons:

             (i) by the Purchaser, if subsequent to September 30, 1999, any
         event shall have occurred which, in the sole judgment of the Purchaser,
         has had, individually or in the aggregate, a Material Adverse Effect,
         or there shall have been, in the sole judgment of the Purchaser, any
         events or developments that, individually or in the aggregate, have or
         could be reasonably likely to have a Material Adverse Effect (except
         for the events disclosed in the SEC Reports or in Schedule 2(e));

             (ii) by the mutual consent of the Purchaser and the Company;

             (iii) by the Purchaser at any time after March 6, 2000 or such
         later date as shall have been agreed to in writing by the parties
         hereto, if at the time notice of such termination is given, the Initial
         Closing shall not have been consummated;

             (iv) solely with respect to the Remaining Preferred Stock, by the
         Purchaser at any time after the expiration of 100 days following the
         Initial Closing (or such later date as shall have been agreed to in
         writing by the parties hereto), if at the time notice of such
         termination is given the Final Closing shall not have been consummated;

             (v) by the Purchaser or the Company if any court of competent
         jurisdiction in the United States or other United States Governmental
         Authority has issued an order, decree or ruling or taken any other
         action restraining, enjoining or otherwise prohibiting the transactions
         contemplated by this Agreement or the other Transaction Documents and
         such order, decree, ruling or other action shall have become final and
         nonappealable provided, that the provisions of this clause (v) shall
         not be available to any party whose failure to fulfill its obligations
         pursuant to this Agreement shall have been the cause of, or shall have
         resulted in, such order, decree, ruling or other action;
<PAGE>   31
                                     - 31 -


             (vi) by the Purchaser, if there has been a material
         misrepresentation or omission or material breach on the part of the
         Company in any of the representations, warranties, covenants or
         agreements of the Company set forth herein or in any other Transaction
         Document, or if there has been any material failure on the part of the
         Company to comply with its obligations and satisfy all conditions on
         its part to be performed or satisfied hereunder at or prior to Closing
         including, without limitation, and solely with respect to the Final
         Closing, obtaining the Stockholder Approval within 100 days after the
         Initial Closing (unless not required as provided in Section 3(e));

             (vii) by the Purchaser, if there has been a suspension in trading
         in securities of the Company or in securities generally on the New York
         Stock Exchange, American Stock Exchange or The Nasdaq Stock Market or
         if minimum or maximum prices shall have been established on any such
         exchange or market;

             (viii) by the Purchaser, if a banking moratorium shall have been
         declared by New York or United States authorities;

             (ix) by the Purchaser, if there has been (A) an outbreak or
         escalation of hostilities between the United States and any foreign
         power, or (B) an outbreak or escalation of any other insurrection or
         armed conflict involving the United States or any other national or
         international calamity or emergency, or (C) any material adverse change
         in (1) the capital markets generally, (2) the capital markets for
         equity securities or (3) the capital markets for telecommunication
         company equity securities which, in the case of (A), (B) or (C) above
         and in the sole judgment of the Purchaser, makes it impracticable or
         inadvisable to proceed with the purchase and sale of the Securities as
         contemplated by this Agreement; or

             (x) by the Purchaser, if third parties, the approvals of which are
         necessary to consummate the transactions contemplated hereby or by the
         other Transaction Documents, require changes to the terms of this
         Agreement or any other Transaction Document that are adverse to the
         Purchaser, as determined by the Purchaser in its sole judgment.

         (b) Termination of this Agreement pursuant to this Section 10 shall be
without liability of any party to any other party except as provided in Sections
5, 8 and 9.

             11. Notices. All communications hereunder shall be in writing and,
if sent to the Purchaser, shall be mailed or delivered or telecopied and
confirmed in writing to the Purchaser at 101 Columbia Road, Morristown, NJ
07960, Attention: Jay
<PAGE>   32
                                     - 32 -


Burden, Telecopier Number (973) 455-6761 with a copy to Morgan Lewis & Bockius,
1701 Market Street, Philadelphia, PA 19103-2921, Attention: John H. Grady,
Telecopier Number (215) 963-5299; if sent to the Company, shall be mailed or
delivered or telecopied and confirmed in writing to the Company at 12975
Worldgate Drive, Herndon, Virginia 21070, Attention: General Counsel, Telecopier
Number (703) 639-6011; with a copy to Davis Polk & Wardwell, Attention: Richard
Drucker, 450 Lexington Avenue, New York, New York 10017, Telecopier Number (212)
474- 3700.

         All such notices and communications shall be deemed to have been duly
given: when delivered by hand, if personally delivered; five business days after
being deposited in the mail, postage prepaid, if mailed; and one business day
after being timely delivered to a next-day air courier; and when receipt is
acknowledged by the addressee, if telecopied.

             12. Successors. This Agreement shall inure to the benefit of and be
binding upon the parties hereto and their respective successors and legal
representatives, and nothing expressed or mentioned in this Agreement is
intended or shall be construed to give any other person any legal or equitable
right, remedy or claim under or in respect of this Agreement, or any provisions
herein contained; this Agreement and all conditions and provisions hereof being
intended to be and being for the sole and exclusive benefit of such persons and
for the benefit of no other person except that the indemnities of the Company
contained in Section 8 of this Agreement shall also be for the benefit of any
Indemnified Party and any person or persons who control the Purchaser within the
meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act.

             13. Subsequent Securities. In addition to the issuance and sale of
the Securities hereunder and any purchase of Securities by Greenwich and Huff,
the Company shall use reasonable efforts to sell to other investors (which
investors shall exclude the Purchaser) acceptable to the Company's Board of
Directors (the "Additional Investors") up to $75,000,000 of additional Preferred
Stock and Warrants (the "Subsequent Securities"), of which up to $25,000,000 of
such Subsequent Securities shall be on the same terms and conditions (including
initial conversion price and initial warrant exercise price) as the Preferred
Stock and Warrants included in the Securities and up to $50,000,000 of such
Subsequent Securities may, if so determined by the Company's Board of Directors,
be on terms and conditions more favorable to the Company. Such purchases will
occur at the Final Closing (or in the event there is no Final Closing, at one or
more closings on mutually convenient dates, times and places, no later than 100
days after the Initial Closing). Such purchases shall be conditioned in addition
to the conditions to the Closings set forth above, upon (i) Stockholder
Approval, and (ii) the execution and delivery by the Additional Purchasers of
definitive commitment letters to the Company covering their investments no later
than March 6, 2000 (with a copy to be delivered by the Company to Purchaser
promptly thereafter).
<PAGE>   33
                                     - 33 -


             14. Equitable Adjustments. In the event that at any time after the
date hereof and prior to the issuance of any Securities or Change in Control
Warrants there shall occur any event which would trigger antidilution
adjustments in connection with such Securities or Change in Control Warrants had
they been previously issued, the number of shares of Common Stock issuable upon
the conversion or exercise thereof, and the conversion or exercise price
applicable thereto, shall be equitably adjusted to reflect such events.

             15. Entire Agreement. This Agreement, together with the Exhibits
and Schedules hereto, the Warrant Agreement and the Registration Rights
Agreement, is intended by the parties as a final and exclusive statement of the
agreement and understanding of the parties hereto in respect of the subject
matter contained herein and therein and any and all prior oral or written
agreements, representations, or warranties, contracts, understandings,
correspondence, conversations and memoranda between the Purchaser on the one
hand and the Company on the other, or between or among any agents,
representatives, parents, subsidiaries, affiliates, predecessors in interest or
successors in interest with respect to the subject matter hereof and thereof are
merged herein and replaced hereby.

             16. Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

             17. APPLICABLE LAW. THE VALIDITY AND INTERPRETATION OF THIS
AGREEMENT, AND THE TERMS AND CONDITIONS SET FORTH HEREIN, SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT
GIVING EFFECT TO ANY PROVISIONS RELATING TO CONFLICTS OF LAW.
<PAGE>   34
                                     - 34 -


             If the foregoing correctly sets forth our understanding, please
indicate your acceptance thereof in the space provided below for that purpose,
whereupon this letter shall constitute a binding agreement between the Company
and the Purchaser.

                                  Very truly yours,


                                  E.SPIRE COMMUNICATIONS, INC.


                                  By: /s/ John R. Polchin
                                      ------------------------------------------
                                  Name: John R. Polchin
                                        ----------------------------------------
                                  Title: Interim Chief Financial Officer
                                         ---------------------------------------


The foregoing Agreement is hereby
confirmed and accepted as of the
date first above written.

HONEYWELL INTERNATIONAL INC.
MASTER RETIREMENT TRUST

By: Northern Trust Company,
    as trustee


By: /s/ Deborah D. Thomas
    ----------------------------------------
Name: Deborah D. Thomas
      --------------------------------------
Title: Senior Vice President & Division Head
       -------------------------------------

                                  The Northern Trust Company executes this
                                  instrument as trustee of aforesaid, and is not
                                  to be held liable in its individual capacity
                                  in any way by reason of this instrument.