Document:

<PAGE>   1

                                                                  EXHIBIT 10.1.3

                               SECOND AMENDMENT TO
                           LOAN AND SECURITY AGREEMENT

         This Second Amendment to Loan and Security Agreement is entered into as
of the execution date stated below, by and between Transamerica Equipment
Financial Services Corporation, a Delaware corporation ("Lender"), whose address
is Riverway II, West Office Tower, 9399 West Higgins Road, Rosemont, Illinois
60018; and Patterson Drilling Company LP, LLLP, a Delaware registered limited
liability limited partnership ("Borrower"), whose executive office is 4510
Lamesa Highway, Snyder, Texas 79549.

A.       Borrower's predecessor-in-interest, Patterson Drilling Company, a
         Delaware corporation, and Lender entered into that certain Loan and
         Security Agreement, dated as of December 21, 1999, for an Existing
         Equipment Loan in the maximum stated principal amount of $50,000,000
         and Equipment Purchase Loan in the aggregate maximum stated principal
         amount of $10,000,000 (the "Loan Agreement"). Capitalized terms not
         specifically defined herein shall have the meanings as defined in the
         Loan Agreement.

B.       On or about December 29, 1999, Borrower and all guarantors completed a
         corporate/entity restructure reconstituting the Borrower and various
         other affiliated entities as limited partnerships or limited liability
         companies. The Borrower subsequently executed a Technical Amendment to
         Loan Documents and Formal Assumption Agreement and, together with the
         undersigned guarantors, executed amendments and reaffirmations of other
         Loan Documents, all executed effective as of December 29, 1999
         (collectively, the "Assumption Documents").

C.       Borrower has requested and Lender has agreed, subject to the terms and
         conditions set forth in this Amendment, to increase the Equipment
         Purchase Loans Limit as stated in the Loan Agreement from $10,000,000
         to $20,000,000.

         NOW, THEREFORE, in consideration of the foregoing premises and the
receipt of other valuable consideration, the receipt and sufficiency of which is
hereby acknowledged, Borrower and Lender hereby agree to amend the Loan
Agreement as follows:

         1. The definition of "Equipment Purchase Loans Limit" in section 1.10
is hereby amended as follows: the phrase "Ten Million and No/00 Dollars
($10,000,000)" is deleted and replaced with "Twenty Million and No/00 Dollars
($20,000,000)."

         2. The definition of "Maximum Credit" in section 1.27 is hereby amended
as follows: the phrase "Sixty Million and No/00 Dollars ($60,000,000)" is
deleted and replaced with "Seventy Million and No/00 Dollars ($70,000,000)."

         3. In section 2.2(a)(ii)(A), the number "$10,000,000" is hereby deleted
and replaced with "$20,000,000."

         4. In section 2.2(d)(iv), the number "$10,000,000" is hereby deleted
and replaced with "$20,000,000."

         5. Notwithstanding anything in section 10.4 of the Loan Agreement to
the contrary, if for any reason, voluntarily or involuntarily, the Loan
Agreement or any provision of this Amendment is terminated or the principal
amounts owing under any Equipment Purchase Note dated after the date of this
Amendment are paid before they are due (a "prepayment"), then in view of the
impracticality and extreme difficulty of ascertaining actual damages and by
mutual agreement of the parties as to a reasonable calculation of Lender's lost
profits as a result thereof, Borrower agrees to pay to Lender, upon the
effective date of such prepayment, a prepayment fee as follows: five percent
(5%) of any prepayment

<PAGE>   2

amount paid prior to February 1, 2001; two percent (2%) of any prepayment amount
paid prior to February 1, 2003; and one percent (1%) of any prepayment amount
paid thereafter.

         6. Borrower represents and warrants to Lender that all Borrower's
representations and warranties in the Loan Documents, as amended and modified by
the Assumption Documents and this Amendment, are true and accurate as of the
date of this Amendment.

         7. Except as modified herein, the Loan Agreement remains in full force
and effect.

         8. This Amendment may be executed in any number of counterparts, each
of which shall be an original and all of which, when taken together, shall
constitute one and the same instrument.

EXECUTED this 20 day of July, 2000.

TRANSAMERICA EQUIPMENT FINANCIAL
SERVICES CORPORATION ("Lender")

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

PATTERSON DRILLING COMPANY LP, LLLP ("Borrower")

By:      PATTERSON (GP) LLC, a Delaware
         limited liability company, its General Partner
         By: /s/ JONATHAN D. NELSON
            ---------------------------------------------
         Printed Name:     Jonathan D. Nelson
                      -----------------------------------
         Title:            Vice President
               ------------------------------------------

The undersigned Guarantors acknowledge and approve the terms of the foregoing
Second Amendment to Loan and Security Agreement. Each Guarantor hereby
represents and warrants to Lender that all its representations and warranties in
the Loan Documents, as amended and modified by the Assumption Documents and this
Amendment are true and accurate as of the date of this Amendment. Each Guarantor
agrees that it remains jointly and severally liable for any and all Obligations
under the Loan Documents, including all amounts contemplated by this Amendment.

<TABLE>
<S>                                              <C>
PATTERSON (GP) LLC,                               PATTERSON ENERGY, INC.
a Delaware limited liability company              a Delaware corporation

By: /s/ JONATHAN D. NELSON                        By: /s/ JONATHAN D. NELSON
   ----------------------------------------           ------------------------------------------------
Printed Name:     Jonathan D. Nelson              Printed Name:     Jonathan D. Nelson
             ------------------------------                    ---------------------------------------
Title:            Vice President                  Title:            Vice President
      -------------------------------------             ----------------------------------------------

PATTERSON (LP) LLC,                               LONE STAR MUD LP, LLLP, a Delaware
a Delaware limited liability company              registered limited liability limited partnership

                                                  By:      Patterson (GP) LLC, a Delaware
By: /s/ ROBERT C. GIST                                     limited liability company, its
   ----------------------------------------                General Partner
Printed Name:     Robert C. Gist
             ------------------------------
Title:            Sole Manager
      -------------------------------------                By: /s/ JONATHAN D. NELSON
                                                              ----------------------------------------
                                                           Printed Name:    Jonathan D. Nelson
                                                                        ------------------------------
                                                           Title:           Vice President
                                                                 -------------------------------------
</TABLE>

                                      -2-<PAGE>   1
                                                                   EXHIBIT 10.16

                                                               EXECUTION VERSION

                 ----------------------------------------------

                 ----------------------------------------------

                          CREDIT AND SECURITY AGREEMENT

                                  BY AND AMONG

                         PENTASTAR COMMUNICATIONS, INC.,

                         PENTASTAR ACQUISITION CORP. I,

                         PENTASTAR ACQUISITION CORP. II,

                        PENTASTAR ACQUISITION CORP. III,

                         PENTASTAR ACQUISITION CORP. IV,

                         PENTASTAR ACQUISITION CORP. VI,

                            PENTASTAR INTERNET, INC.,

                         PENTASTAR HOLDING CORPORATION,

                          PENTASTAR TELEMARKETING, INC.

                                       AND

                             PENTASTAR CORPORATION,

                                  AS BORROWERS

                                       AND

                           WELLS FARGO BANK WEST, N.A.

                           Dated as of: July 10, 2000

                 ----------------------------------------------

                 ----------------------------------------------

<PAGE>   2
Table of Contents

<TABLE>
<CAPTION>
                                                                                                Page
                                                                                                ----
<S>      <C>               <C>                                                                   <C>
ARTICLE I  Definitions                                                                            1
         Section 1.1       Definitions                                                            1
         Section 1.2       Cross References                                                       8

ARTICLE II  Amount and Terms of the Credit Facility                                               9
         Section 2.1       Advances 9
         Section 2.2       Interest; Default Interest.                                            9
         Section 2.3       Fees                                                                  10
         Section 2.4       Computation of Interest and Fees; When Interest Due and Payable       10
         Section 2.5       Capital Adequacy                                                      10
         Section 2.6       Voluntary Prepayment; Reduction of the Maximum Line; Termination
                           of the Credit Facility by the Borrowers                               11
         Section 2.7       Mandatory Prepayment                                                  11
         Section 2.8       Payment on Non-Banking Days                                           12
         Section 2.9       Use of Proceeds                                                       12
         Section 2.10      Liability Records                                                     12

ARTICLE III  Security Interest; Occupancy; Setoff                                                12
         Section 3.1       Grant of Security Interest                                            12
         Section 3.2       Notification of Account Debtors and Other Obligors                    12
         Section 3.3       Assignment of Insurance                                               13
         Section 3.4       Occupancy                                                             13
         Section 3.5       License                                                               14
         Section 3.6       Setoff                                                                14

ARTICLE IV  Conditions of Lending                                                                14
         Section 4.1       Conditions Precedent to the Initial Advance                           14
         Section 4.2       Conditions Precedent to All Advances                                  15

ARTICLE V  Representations and Warranties                                                        16

         Section 5.1       Corporate Existence and Power; Name; Chief Executive Office;
                           Inventory and Equipment Locations; Tax Identification Number          16
         Section 5.2       Authorization of Borrowing; No Conflict as to Law or Agreements       16
         Section 5.3       Legal Agreements                                                      16
         Section 5.4       Subsidiaries                                                          17
         Section 5.5       Financial Condition; No Adverse Change                                17
         Section 5.6       Litigation                                                            17
         Section 5.7       Regulation U                                                          17
         Section 5.8       Taxes                                                                 17
         Section 5.9       Titles and Liens                                                      17
         Section 5.10      Plans                                                                 18
         Section 5.11      Default                                                               18
         Section 5.12      Environmental Matters                                                 18
         Section 5.13      Submissions to Lender                                                 19
         Section 5.14      Financing Statements                                                  19
         Section 5.15      Rights to Payment                                                     20
         Section 5.16      Financial Solvency                                                    20
</TABLE>

                                       i
<PAGE>   3
<TABLE>
<CAPTION>
                                                                                                Page
                                                                                                ----
<S>      <C>               <C>                                                                   <C>
ARTICLE VI  Borrowers' Affirmative Covenants                                                     21
         Section 6.1       Reporting Requirements                                                21
         Section 6.2       Books and Records; Inspection and Examination                         24
         Section 6.3       Account Verification                                                  24
         Section 6.4       Compliance with Laws                                                  24
         Section 6.5       Payment of Taxes and Other Claims                                     25
         Section 6.6       Maintenance of Properties                                             25
         Section 6.7       Insurance                                                             25
         Section 6.8       Preservation of Existence                                             26
         Section 6.9       Delivery of Instruments, etc.                                         26
         Section 6.10      Performance by the Lender                                             26
         Section 6.11      Minimum Current Ratio                                                 26
         Section 6.12      Total Leverage Ratio                                                  27

ARTICLE VII  Negative Covenants                                                                  28
         Section 7.1       Liens                                                                 28
         Section 7.2       Indebtedness                                                          29
         Section 7.3       Guaranties                                                            29
         Section 7.4       Investments and Subsidiaries                                          29
         Section 7.5       Dividends                                                             30
         Section 7.6       Sale or Transfer of Assets; Suspension of Business Operations         30
         Section 7.7       Consolidation and Merger; Asset Acquisitions                          30
         Section 7.8       Sale and Leaseback                                                    31
         Section 7.9       Restrictions on Nature of Business                                    31
         Section 7.10      Accounting                                                            31
         Section 7.11      Defined Benefit Pension Plans                                         31
         Section 7.12      Other Defaults                                                        31
         Section 7.13      Place of Business; Name                                               31
         Section 7.14      Organizational Documents                                              31

ARTICLE VIII  Events of Default, Rights and Remedies                                             31
         Section 8.1       Events of Default                                                     31
         Section 8.2       Rights and Remedies                                                   33
         Section 8.3       Certain Notices                                                       34

ARTICLE IX  Miscellaneous                                                                        34
         Section 9.1       No Waiver; Cumulative Remedies                                        34
         Section 9.2       Amendments, Etc.                                                      35
         Section 9.3       Addresses for Notices, Etc.                                           35
         Section 9.4       Further Documents                                                     36
         Section 9.5       Collateral                                                            36
         Section 9.6       Costs and Expenses                                                    36
         Section 9.7       Indemnity                                                             36
         Section 9.8       Participants                                                          37
         Section 9.9       Execution in Counterparts                                             37
         Section 9.10      Binding Effect; Assignment; Complete Agreement; Exchanging
                           Information                                                           37
         Section 9.11      Severability of Provisions                                            38
         Section 9.12      Headings                                                              38
         Section 9.13      Governing Law; Jurisdiction, Venue; Waiver of Jury Trial              38
         Section 9.14      Joint and Several Liability                                           39
         Section 9.15.     Contribution and Indemnification among the Borrowers                  40
         Section 9.16      Agency of the Parent for each other Borrower                          41
</TABLE>

                                       ii

<PAGE>   4

                          CREDIT AND SECURITY AGREEMENT

Dated as of July 10, 2000

         PentaStar Communications, Inc., a Delaware corporation, PentaStar
Acquisition Corp. I, a Delaware corporation, PentaStar Acquisition Corp. II, a
Delaware corporation, PentaStar Acquisition Corp. III, a Delaware corporation,
PentaStar Acquisition Corp. IV, a Delaware corporation, PentaStar Acquisition
Corp. VI, a Delaware corporation, PentaStar Internet, Inc., a Delaware
corporation, PentaStar Holding Corporation, a Delaware corporation, PentaStar
Telemarketing, Inc., a Delaware corporation, and PentaStar Corporation, a
Colorado corporation (each of the foregoing a "Borrower" and collectively the
"Borrowers"), and Wells Fargo Bank West, N.A., a national banking association
(the "Lender"), hereby agree as follows:

                                    ARTICLE I

                                  Definitions

(ii1          Section Definitions . For all purposes of this Agreement, except
as otherwise expressly provided or unless the context otherwise requires:

(ii2

                  (a) the terms defined in this Article have the meanings
         assigned to them in this Article, and include the plural as well as the
         singular; and

                  (b) all accounting terms not otherwise defined herein have the
         meanings assigned to them in accordance with GAAP.

                  "Accounts" means all of the Borrowers' accounts, as such term
         is defined in the UCC, including without limitation the aggregate
         unpaid obligations of customers and other account debtors to any
         Borrower arising out of the sale or lease of goods or rendition of
         services by any Borrower on an open account or deferred payment basis.

                  "Advance" has the meaning given in Section 2.1.

                  "Affiliate" or "Affiliates" means any Person controlled by,
         controlling or under common control with any Borrower, including
         (without limitation) any Subsidiary of any Borrower. For purposes of
         this definition, "control," when used with respect to any specified
         Person, means the power to direct the management and policies of such
         Person, directly or indirectly, whether through the ownership of voting
         securities, by contract or otherwise.

                  "Agreement" means this Credit and Security Agreement, as
         amended, supplemented or restated from time to time.

                  "Auditor" means Arthur Anderson, or another independent
         accounting firm acceptable to the Borrowers and the Lender.

                  "Banking Day" means a day other than a Saturday, Sunday or
         other day on which banks are generally not open for business in Denver,
         Colorado.

                  "Borrowing Base" means at any time the lesser of:

                  (a) the Maximum Line; or

                  (b) subject to change from time to time in the Lender's
         reasonable discretion, 75% of Eligible Accounts.

                  "Collateral" means all of each Borrower's Equipment, General
         Intangibles, Inventory, Receivables (including without limitation all
         Accounts) and Investment Property; together with (i) all substitutions
         and replacements for and products of any of the foregoing; (ii)
         proceeds of any and all of the foregoing; (iii) in the case of all
         tangible goods, all accessions; and (iv) all accessories, attachments,
         parts, equipment and

                                       1
<PAGE>   5

         repairs now or hereafter attached or affixed to or used in connection
         with any tangible goods; provided that Collateral shall not include
         property encumbered by the Merrill Lynch Lien.

                  "Commitment" means the Lender's commitment to make Advances to
         or for the Borrowers' account pursuant to Article II.

                  "Credit Facility" means the credit facility being made
         available to the Borrowers by the Lender pursuant to Article II.

                  "Current Ratio" as of a given date means the ratio of the
         Borrowers' consolidated current assets to the Borrowers' consolidated
         current liabilities (excluding the outstanding principal balance of the
         Note and the Merrill Lynch Long Term Debt), each as determined in
         accordance with GAAP.

                  "Debt" of any Person means all items of indebtedness or
         liability which in accordance with GAAP would be included in
         determining total liabilities as shown on the liabilities side of a
         balance sheet of that Person as at the date as of which Debt is to be
         determined. For purposes of determining a Person's aggregate Debt at
         any time, "Debt" shall also include the aggregate payments required to
         be made by such Person at any time under any lease that is considered a
         capitalized lease under GAAP.

                  "Default" means an event that, with giving of notice or
         passage of time or both, would constitute an Event of Default.

                  "Default Rate" means an annual rate equal to three percent
         (3%) over the otherwise applicable interest rate, which Default Rate
         shall change when and as such applicable interest rate changes.

                  "EBITDA" for a period means the sum of (i) pretax earnings
         from continuing operations, (ii) Interest Expense and (iii)
         depreciation, depletion, and amortization of tangible and intangible
         assets, before (a) special extraordinary gains and losses and (b)
         minority interests, in each case for such period, computed and
         calculated in accordance with GAAP.

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

                  "Eligible Accounts" means all unpaid Net Accounts, net of any
         credits, except the following shall not in any event be deemed Eligible
         Accounts:

                           (i)      that portion of Accounts (a) relating to
                                    which the Account debtor is refusing to pay
                                    or is asserting is not due and payable or
                                    (b) subject to a claim of offset or a contra
                                    account; provided that no Account or portion
                                    thereof shall be excluded by virtue of this
                                    clause (i) if such Account or portion
                                    thereof has already been discounted due to
                                    the reserve for disputed accounts in
                                    accordance with the definition of Net
                                    Accounts;

                           (ii)     that portion of Accounts not yet earned by
                                    the final delivery of goods or rendition of
                                    services, as applicable, by any Borrower to
                                    the customer;

                           (iii)    accounts due from any United States federal
                                    governmental entity or other governmental
                                    entity in the United States for which any
                                    special procedures must be complied with in
                                    order to obtain a valid perfected first
                                    priority security interest in such Account,
                                    which special procedures have not been
                                    complied with;

                           (iv)     accounts owed by an account debtor located
                                    anywhere outside the United States,
                                    including without limitation, any unit of
                                    any foreign government;

                           (v)      accounts owed by an account debtor that is
                                    insolvent, the subject of bankruptcy
                                    proceedings or has gone out of business;

                                       2
<PAGE>   6

                           (vi)     accounts owed by a shareholder, Subsidiary,
                                    Affiliate, officer or employee of any
                                    Borrower;

                           (vii)    accounts not subject to a duly perfected
                                    security interest in the Lender's favor or
                                    which are subject to any lien, security
                                    interest or claim in favor of any Person
                                    other than the Lender including without
                                    limitation any payment or performance bond;

                           (viii)   that portion of Accounts that constitutes
                                    advertising, finance charges or sales or
                                    excise taxes;

                           (ix)     that portion of any Accounts with respect to
                                    which any Borrower guarantees the repurchase
                                    of the inventory or goods giving rise to
                                    such Account;

                           (x)      Accounts subject to the Merrill Lynch Lien;

                           (xi)     Accounts resulting from or arising out of
                                    any acquisition by any Borrower after the
                                    date hereof which Accounts have not been (i)
                                    audited by the Auditor or any national
                                    independent accounting firm within 60 days
                                    of the closing of such acquisition, or (ii)
                                    if not audited by the Auditor or such
                                    national independent accounting firm within
                                    such 60 day period, then audited by Lender's
                                    internal auditor if Lender so chooses in its
                                    reasonable discretion within 30 days of the
                                    end of such 60 day period; and

                           (xii)    Accounts, or portions thereof, otherwise
                                    deemed ineligible by the Lender in its
                                    reasonable discretion.

                  "Environmental Laws" has the meaning specified in Section
         5.12.

                  "Equipment" means all of the Borrowers' equipment, as such
         term is defined in the UCC, whether now owned or hereafter acquired,
         including but not limited to all present and future machinery,
         vehicles, furniture, fixtures, office and record keeping equipment and
         supplies.

                  "Event of Default" has the meaning specified in Section 8.1.

                  "Funded Debt" means, with respect to any Person or Persons at
         any date, without duplication, all Debt of such Person or Persons that
         constitutes (a) all obligations of such Person or Persons for borrowed
         money, letters of credit (or applications for letters of credit) or
         other similar instruments, (b) all obligations of such Person or
         Persons evidenced by bonds, debentures, notes or other similar
         instruments, excluding any surety or performance bonds, (c) all
         obligations of such Person or Persons to pay the deferred purchase
         price of property or services, but only if such deferral is in excess
         of 90 days, (d) all obligations under capital leases of such Person or
         Persons, (e) installment payment non-compete agreements for such Person
         or Persons, and (f) any obligation or guaranty, contingent or
         otherwise, of such Person guaranteeing or having the economic effect of
         guaranteeing any Debt or obligation of any other Person in any manner,
         whether directly or indirectly, relating to obligations of such other
         Person (other than any Borrower with respect to Debt of another
         Borrower) of the type described in (a) through (e) above.

                  "GAAP" means generally accepted accounting principles, applied
         on a basis consistent with the accounting practices applied in the
         financial statements described in Section 5.5.

                  "General Intangibles" means all of the Borrowers' general
         intangibles, as such term is defined in the UCC, whether now owned or
         hereafter acquired, including (without limitation) all present and
         future patents, patent applications, copyrights, trademarks, trade
         names, trade secrets, customer or supplier lists and contracts,
         manuals, operating instructions, permits, franchises, the right to use
         any Borrower's name, and the goodwill of the Borrowers' businesses.

                                       3
<PAGE>   7

                  "Hazardous Substance" has the meaning given in Section 5.12.

                  "Interest Expense" means, for a fiscal year-to-date period,
         the Borrowers' total gross interest expense during such period
         (excluding interest income), and shall in any event include, without
         limitation, (i) interest expensed (whether or not paid) on all Debt,
         (ii) the amortization of debt discounts, (iii) the amortization of all
         fees payable in connection with the incurrence of Debt to the extent
         included in interest expense, and (iv) the portion of any capitalized
         lease obligation allocable to interest expense.

                  "Inventory" means all of the Borrowers' inventory, as such
         term is defined in the UCC, whether now owned or hereafter acquired,
         whether consisting of whole goods, spare parts or components, supplies
         or materials, whether acquired, held or furnished for sale, for lease
         or under service contracts or for manufacture or processing, and
         wherever located.

                  "Investment Property" means all of the Borrowers' investment
         property, as such term is defined in the UCC, whether now owned or
         hereafter acquired, including but not limited to all securities,
         security entitlements, securities accounts, commodity contracts,
         commodity accounts, stocks, bonds, mutual fund shares, money market
         shares and U.S. Government securities.

                  "Liens" shall have the meaning set forth in Section 7.1.

                  "Loan Documents" means this Agreement, the Note and the
         Security Documents.

                  "Maturity Date" means July 31, 2001.

                  "Maximum Line" means $10,000,000.00, unless said amount is
         reduced pursuant to Section 2.6, in which event it means the amount to
         which said amount is reduced.

                  "Merrill Lynch Credit Agreement" has the meaning in the
         definition of "Merrill Lynch Loan Documents".

                  "Merrill Lynch Lien" means the lien in favor of Merrill Lynch
         Business Financial Services Inc., created pursuant to the Merrill Lynch
         Loan Documents, in all of the following property and interests in
         property of PentaStar Corporation: all Accounts, Contract Rights and
         General Intangibles due from, related to or to be collected from
         Ameritech Information Systems Inc. ("Ameritech") in connection with the
         Authorized Distributor Agreement between Ameritech and Telcomm
         Industries, Inc. ("Telecomm") dated effective January 1, 1999 (the
         "Authorized Distributor Agreement") and any other distributor
         agreements between Ameritech and Telecomm (collectively "Distributor
         Agreements"), which such Distributor Agreements have been or are to be
         assigned by Telecomm to PentaStar Corporation in connection with
         PentaStar Corporation's acquisition of some of the assets of Telecomm
         in July 2000, but only to the extent that such Accounts, Contract
         Rights and General Intangibles were, on or prior to June 30, 2000,
         either (i) desginated by Ameritech as "Residual Payments" (which term
         shall mean both "Residual Payments" as defined in the Authorized
         Distributor Agreement and any other similar term used by Ameritech in a
         Distributor Agreement representing the right to the same type of
         payments as a "Residual Payment" under the Authorized Distributor
         Agreement) or (ii) represented on the books of PentaStar Corporation as
         Residual Payments due or earned from Ameritech, together with all books
         and records (including computer records) directly related thereto and
         all proceeds thereof; provided that, for the avoidance of doubt, the
         Merrill Lynch Lien shall not encumber any Accounts, Contract Rights or
         General Intangibles or any other rights related to or in connection
         with any "Base Commission" or "Upfront Commission Payment" (as each
         such term is defined in Exhibit C to the Authorized Distributor
         Agreement).

                  "Merrill Lynch Long Term Debt" means the debt evidenced by the
         Merrill Lynch Loan Documents.

                                       4
<PAGE>   8

                  "Merrill Lynch Loan Documents" means the WCMA REDUCING
         REVOLVER sm Loan and Security Agreement NO. 613-07E50 dated as of July
         17, 2000, between PENTASTAR CORPORATION and MERRILL LYNCH BUSINESS
         FINANCIAL SERVICES INC. (as such agreement exists on July 17, 2000, the
         "Merrill Lynch Credit Agreement") and all related documents.

                  "Net Accounts" means all of the Borrowers' Accounts, less a
         reserve for disputed accounts as calculated or adjusted by the
         Borrowers from time to time and confirmed by the Auditor.

                  "Note" means the Borrowers' revolving promissory note, payable
         to the order of the Lender in substantially the form of Exhibit A
         hereto, as the same may hereafter be amended, supplemented or restated
         from time to time, and any note or notes issued in substitution
         therefor, as the same may hereafter be amended, supplemented or
         restated from time to time and any note or notes issued in substitution
         therefor.

                  "Obligations" shall mean all obligations and liabilities of
         the Borrowers under or in connection with the Loan Documents, now
         existing or hereafter created, contingent or not, due or not, arising
         by operation of law or otherwise.

                  "Parent" means PentaStar Communications, Inc.

                  "Permitted Acquisition" means any acquisition made by the
         Parent, or a wholly owned Subsidiary of the Parent that is or becomes a
         Borrower under this Agreement, of 100% of the assets or capital stock
         of a Person operating in the same line of business as the Parent.

                  "Permitted Lien" has the meaning given in Section 7.1.

                  "Person" means any individual, corporation, partnership, joint
         venture, limited liability company, association, joint-stock company,
         trust, unincorporated organization or government or any agency or
         political subdivision thereof.

                  "Plan" means an employee benefit plan or other plan maintained
         for any Borrower's employees and covered by Title IV of ERISA.

                  "Premises" means all premises where any Borrower conducts its
         business and has any rights of possession.

                  "Receivables" means each and every right of any Borrower to
         the payment of money, whether such right to payment now exists or
         hereafter arises, whether such right to payment arises out of a sale,
         lease or other disposition of goods or other property, out of a
         rendering of services, out of a loan, out of the overpayment of taxes
         or other liabilities, or otherwise arises under any contract or
         agreement, whether such right to payment is created, generated or
         earned by any Borrower or by some other person who subsequently
         transfers such person's interest to any Borrower, whether such right to
         payment is or is not already earned by performance, and howsoever such
         right to payment may be evidenced, together with all other rights and
         interests (including all liens and security interests) which any
         Borrower may at any time have by law or agreement against any account
         debtor or other obligor obligated to make any such payment or against
         any property of such account debtor or other obligor; all including but
         not limited to all present and future accounts, contract rights, loans
         and obligations receivable, chattel papers, bonds, notes and other debt
         instruments, tax refunds and rights to payment in the nature of general
         intangibles.

                  "Reportable Event" shall have the meaning assigned to that
         term in Title IV of ERISA.

                  "Security Documents" means this Agreement and any other
         document delivered to the Lender from time to time to secure the
         Obligations, as the same may hereafter be amended, supplemented or
         restated from time to time.

                  "Security Interest" has the meaning given in Section 3.1.

                                       5
<PAGE>   9

                  "Subsidiary" means any corporation of which more than 50% of
         the outstanding shares of capital stock having general voting power
         under ordinary circumstances to elect a majority of the board of
         directors of such corporation, irrespective of whether or not at the
         time stock of any other class or classes shall have or might have
         voting power by reason of the happening of any contingency, is at the
         time directly or indirectly owned by any Borrower, by any Borrower and
         one or more other Subsidiaries, or by one or more other Subsidiaries.

                  "Termination Date" means the earliest of (i) the Maturity
         Date, (ii) the date any Borrower terminates the Credit Facility, or
         (iii) the date the Lender demands payment of the Obligations (or such
         Obligations become automatically due and payable) after an Event of
         Default pursuant to Section 8.2.

                  "UCC" means the Uniform Commercial Code as in effect from time
         to time in the state designated in Section 9.13 as the state whose laws
         shall govern this Agreement, or in any other state whose laws are held
         to govern this Agreement or any portion hereof.

                  Section 1.2 Cross References . All references in this
Agreement to Articles, Sections and subsections, shall be to Articles, Sections
and subsections of this Agreement unless otherwise explicitly specified.

                                       6
<PAGE>   10

                                   ARTICLE II

                     Amount and Terms of the Credit Facility

                  Section 2.1 Advances . The Lender agrees, on the terms and
subject to the conditions herein set forth, to make advances to the Borrowers
from time to time from the date all of the conditions set forth in Section 4.1
are satisfied until the Termination Date, on the terms and subject to the
conditions herein set forth (the "Advances"). The Lender shall have no
obligation to make an Advance if, after giving effect to such requested Advance,
the sum of the outstanding and unpaid Advances would exceed the Borrowing Base.
The Borrowers' obligation to pay the Advances shall be evidenced by the Note and
shall be secured by the Collateral as provided in Article III. Within the limits
set forth in this Section 2.1, the Borrowers may borrow, prepay pursuant to
Section 2.6 and reborrow. The Borrowers agree to comply with the following
procedures in requesting Advances under this Section 2.1:

                  (a) The Borrowers shall make each request for an Advance to
         the Lender before 11:00 a.m. (Denver time) of the day of the requested
         Advance. Requests may be made in writing or by telephone, specifying
         the date of the requested Advance and the amount thereof. Each request
         shall be by (i) any officer of the Parent; or (ii) any person
         designated as the Parent's agent by any officer of the Parent in a
         writing delivered to the Lender; or (iii) any person whom the Lender
         reasonably believes to be an officer of the Parent or such a designated
         agent.

                  (b) Upon fulfillment of the applicable conditions set forth in
         Article IV, the Lender shall disburse the proceeds of the requested
         Advance by crediting the same to the Parent's demand deposit account
         maintained with Lender (Account No. 1018234328) unless the Lender and
         the Borrowers shall agree in writing to another manner of disbursement.
         Upon the Lender's request, the Parent shall promptly confirm each
         telephonic request for an Advance by executing and delivering an
         appropriate confirmation certificate to the Lender. The Borrowers shall
         repay all Advances even if the Lender does not receive such
         confirmation and even if the person requesting an Advance was not in
         fact authorized to do so. Any request for an Advance, whether written
         or telephonic, shall be deemed to be a representation by the Borrowers
         that the conditions set forth in Section 4.2 have been satisfied as of
         the time of the request.

                  Section 2.2 Interest; Default Interest.

                  (a) INTEREST. Subject to Section 2.2(b), the outstanding
         principal balance of the Note shall bear interest, and such interest
         shall be due and payable, as set forth in the Note. All interest due
         and payable under the Note shall be debited from the Borrowers'
         account.

                  (b) DEFAULT INTEREST RATE. At any time during which any
         Default or Event of Default shall have occurred and be continuing, in
         the Lender's sole discretion and without waiving any of its other
         rights and remedies, the principal of the Advances outstanding from
         time to time shall bear interest at the Default Rate.

                  Section 2.3 Fees.

                  (a) ORIGINATION FEE. The Borrowers hereby agree to pay the
         Lender a fully earned and non-refundable origination fee of $25,000,
         due and payable upon the execution of this Agreement.

                  (b) UNUSED LINE FEE. For the purposes of this Section 2.3(b),
         "Unused Amount" means the Maximum Line reduced by outstanding Advances.
         The Borrowers agree to pay to the Lender an unused line fee at the rate
         of one quarter of one percent (.25%) per annum on the average daily
         Unused Amount from the date of this Agreement to and including the
         Termination Date, due and payable quarterly in arrears on the first day
         of the quarter and on the Termination Date. All fees due and payable
         under this Section 2.3(b) shall be debited from the Borrowers' account.

                  (c) AUDIT FEES. The Borrowers hereby agree to pay the Lender
         or the Auditor, as applicable, on demand, reasonable audit fees in
         connection with any audits or inspections conducted by the Lender or
         the Auditor of any Accounts, Collateral or any Borrower's operations or
         business at the rates established

                                       7
<PAGE>   11

         from time to time by the Lender as its audit fees, together with all
         actual reasonable out-of-pocket costs and expenses incurred in
         conducting any such audit or inspection.

                  Section 2.4 Computation of Interest and Fees; When Interest
Due and Payable . Interest accruing on the outstanding principal balance of the
Advances and fees hereunder outstanding from time to time shall be computed on
the basis of actual number of days elapsed in a year of 360 days. Interest shall
be payable in arrears on the first day of each month and on the Termination
Date.

                  Section 2.5 Capital Adequacy . If any Related Lender
reasonably determines at any time that its Return has been reduced as a result
of any Rule Change, such Related Lender may require the Borrowers to pay it the
amount necessary to restore its Return to what it would have been had there been
no Rule Change. For purposes of this Section 2.5:

                  (a) "Capital Adequacy Rule" means any law, rule, regulation,
         guideline, directive, requirement or request regarding capital
         adequacy, or the interpretation or administration thereof by any
         governmental or regulatory authority, central bank or comparable
         agency, whether or not having the force of law, that applies to any
         Related Lender. Such rules include rules requiring financial
         institutions to maintain total capital in amounts based upon
         percentages of outstanding loans, binding loan commitments and letters
         of credit.

                  (b) "Return," for any period, means the return as determined
         by such Related Lender on the Advances based upon its total capital
         requirements and a reasonable attribution formula that takes account of
         the Capital Adequacy Rules then in effect. Return may be calculated for
         each calendar quarter and for the shorter period between the end of a
         calendar quarter and the date of termination in whole of this
         Agreement.

                  (c) "Rule Change" means any change in any Capital Adequacy
         Rule occurring after the date of this Agreement, but the term does not
         include any changes in applicable requirements that at the Closing Date
         are scheduled to take place under the existing Capital Adequacy Rules
         or any increases in the capital that any Related Lender is required to
         maintain to the extent that the increases are required due to a
         regulatory authority's assessment of the financial condition of such
         Related Lender.

                  (d) "Related Lender" includes (but is not limited to) the
         Lender, any parent corporation of the Lender and any assignee of any
         interest of the Lender hereunder and any participant in the loans made
         hereunder.

Certificates of any Related Lender sent to any Borrower from time to time
claiming compensation under this Section 2.5, stating the reason therefor and
setting forth in reasonable detail the calculation of the additional amount or
amounts to be paid to the Related Lender hereunder to restore its Return, shall
be conclusive absent manifest error. In determining such amounts, the Related
Lender may use any reasonable averaging and attribution methods.

                  Section 2.6 Voluntary Prepayment; Reduction of the Maximum
Line; Termination of the Credit Facility by the Borrowers . Except as otherwise
provided herein and subject to all applicable provisions in the Note, the
Borrowers may prepay the Advances in whole at any time or in part from time to
time. The Borrowers may terminate the Credit Facility in whole (but not in part)
at any time and, subject to payment and performance of all the Borrowers'
obligations to the Lender (including without limitation all obligations under
the Note), may obtain any release or termination of the Security Interest to
which the Borrowers are otherwise entitled by law by giving at least 30 days'
prior written notice to the Lender of the Borrowers' intention to terminate this
Agreement. The Borrowers may not decrease the Maximum Line other than in
connection with a prepayment in full of the Advances and termination of the
Credit Facility in full, as set forth above.

                  Section 2.7 Mandatory Prepayment . Without notice or demand,
if the outstanding principal balance of the Advances shall at any time exceed
the Borrowing Base, the Borrowers shall immediately prepay the Advances to the
extent necessary to eliminate such excess. Any payment received by the Lender
under this

                                       8
<PAGE>   12

Section 2.7 or under Section 2.6 may be applied to the Obligations, in such
order and in such amounts as the Lender, in its discretion, may from time to
time determine.

                  Section 2.8 Payment on Non-Banking Days . Whenever any payment
to be made hereunder shall be stated to be due on a day which is not a Banking
Day, such payment may be made on the next succeeding Banking Day, and such
extension of time shall in such case be included in the computation of interest
on the Advances or the fees hereunder, as the case may be.

                  Section 2.9 Use of Proceeds . The Borrowers shall use the
proceeds of Advances to finance future acquisitions, purchases of fixed assets
and for ordinary working capital purposes.

                  Section 2.10 Liability Records . The Lender may maintain from
time to time, at its discretion, liability records as to the Obligations. All
entries made on any such record shall be presumed correct until any Borrower
establishes the contrary. Upon the Lender's demand, each Borrower will admit and
certify in writing the exact principal balance of the Obligations that such
Borrower then asserts to be outstanding. Any billing statement or accounting
rendered by the Lender shall be conclusive and fully binding on the Borrowers
unless the Borrowers give the Lender specific written notice of exception within
30 days after receipt.

                                   ARTICLE III

                      Security Interest; Occupancy; Setoff

                  Section 3.1 Grant of Security Interest . Each of the Borrowers
hereby pledges, assigns and grants to the Lender a security interest
(collectively referred to as the "Security Interest") in the Collateral, as
security for the payment and performance of the Obligations.

                  Section 3.2 Notification of Account Debtors and Other
Obligors. Upon the occurrence of an Event of Default, the Lender may at any time
(whether or not a Default or Event of Default then exists) notify any account
debtor or other person obligated to pay the amount due that such right to
payment has been assigned or transferred to the Lender for security and shall be
paid directly to the Lender. The Borrowers will join in giving such notice if
the Lender so requests. At any time after any Borrower or the Lender gives such
notice to an account debtor or other obligor, the Lender may, but need not, in
the Lender's name or in the relevant Borrower's name, (a) demand, sue for,
collect or receive any money or property at any time payable or receivable on
account of, or securing, any such right to payment, or grant any extension to,
make any compromise or settlement with or otherwise agree to waive, modify,
amend or change the obligations (including collateral obligations) of any such
account debtor or other obligor; and (b) as each Borrower's agent and
attorney-in-fact, notify the United States Postal Service to change the address
for delivery of each Borrower's mail to any address designated by the Lender,
otherwise intercept each Borrower's mail, and receive, open and dispose of each
Borrower's mail, applying all Collateral as permitted under this Agreement and
holding all other mail for each Borrower's account or forwarding such mail to
each Borrower's last known address.

                  Section 3.3 Assignment of Insurance . As additional security
for the payment and performance of the Obligations, each of the Borrowers hereby
assigns to the Lender any and all monies (including, without limitation,
proceeds of insurance and refunds of unearned premiums) due or to become due
under, and all other rights of the Borrowers with respect to, any and all
policies of insurance now or at any time hereafter covering the Collateral or
any evidence thereof or any business records or valuable papers pertaining
thereto, and each of the Borrowers hereby directs the issuer of any such policy
to pay all such monies directly to the Lender. Upon the occurrence of an Event
of Default, the Lender may (but need not), in the Lender's name or in any
Borrower's name, execute and deliver proof of claim, receive all such monies,
endorse checks and other instruments representing payment of such monies, and
adjust, litigate, compromise or release any claim against the issuer of any such
policy.

                  Section 3.4 Occupancy .

                  (a) Each Borrower hereby irrevocably grants to the Lender the
         right to enter and occupy the Premises at any time after the occurrence
         and during the continuance of an Event of Default.

                                       9
<PAGE>   13

                  (b) The Lender may use the Premises only to hold, process,
         manufacture, sell, use, store, liquidate, realize upon or otherwise
         dispose of goods that are Collateral and for other purposes that the
         Lender may in good faith deem to be related or incidental purposes.

                  (c) The Lender's right to occupy the Premises shall cease and
         terminate upon the earlier of (i) payment in full and discharge of all
         Obligations and termination of the Commitment, (ii) final sale or
         disposition of all goods constituting Collateral and delivery of all
         such goods to purchasers, and (iii) the termination or cure of such
         Event of Default giving rise to such right.

                  (d) The Lender shall not be obligated to pay or account for
         any rent or other compensation for the possession, occupancy or use of
         any of the Premises; provided, however, that if the Lender does pay or
         account for any rent or other compensation for the possession,
         occupancy or use of any of the Premises, the Borrowers shall reimburse
         the Lender promptly for the full amount thereof. In addition, the
         Borrowers will pay, or reimburse the Lender for, all taxes, fees,
         duties, imposts, charges and expenses at any time incurred by or
         imposed upon the Lender by reason of the execution, delivery,
         existence, recordation, performance or enforcement of this Agreement or
         the provisions of this Section 3.4.

                  Section 3.5 License . The Borrowers hereby grant to the Lender
a non-exclusive, worldwide and royalty-free license to use or otherwise exploit
all trademarks, franchises, trade names, copyrights and patents of any Borrower
for the purpose of selling, leasing or otherwise disposing of any or all
Collateral after the occurrence of a Default or Event of Default.

                  Section 3.6 Setoff . The Borrowers hereby confirm the Lender's
rights (and the rights of each other Person holding a participating interest in
any Obligations) of banker's lien and setoff and nothing in this Agreement, or
any other Loan Document shall be deemed a waiver, limitation or prohibition of
such right of banker's lien or setoff.

                                   ARTICLE IV

                              Conditions of Lending

                  Section 4.1 Conditions Precedent to the Initial Advance . The
Lender's obligation to make the initial Advance hereunder shall be subject to
the condition precedent that the Lender shall have received all of the
following, each in form and substance satisfactory to the Lender:

                  (a) This Agreement, properly executed by the Borrowers.

                  (b) The Note, properly executed by the Borrowers.

                  (c) A true and correct copy of any and all leases pursuant to
         which any Borrower is leasing any Premises at such Borrower's principal
         place of business as set forth on Schedule 5.1, together with a
         landlord's disclaimer and consent with respect to the Parent's lease of
         the Premises located at 1522 Blake Street, Denver, CO.

                  (d) Current searches of appropriate filing offices showing
         that (i) no state or federal tax liens have been filed and remain in
         effect against any Borrower, (ii) no financing statements or
         assignments of patents, trademarks or copyrights have been filed and
         remain in effect against any Borrower except those financing statements
         and assignments of patents, trademarks or copyrights relating to
         Permitted Liens or to liens held by Persons who have agreed in writing
         that upon receipt of proceeds of the Advances, they will deliver UCC
         releases and/or terminations and releases of such assignments of
         patents, trademarks or copyrights satisfactory to the Lender, and (iii)
         the Lender has duly filed all financing statements necessary to perfect
         the Security Interest, to the extent the Security Interest is capable
         of being perfected by filing.

                  (e) A certificate of each Borrower's Secretary or Assistant
         Secretary attaching and certifying as to (i) the resolutions of such
         Borrower's directors and, if required, shareholders, authorizing the
         execution, delivery and performance of the Loan Documents, (ii) such
         Borrower's articles of incorporation

                                       10
<PAGE>   14

         and bylaws, and (iii) the signatures of such Borrower's officers or
         agents authorized to execute and deliver the Loan Documents and other
         instruments, agreements and certificates, including Advance requests,
         on such Borrower's behalf.

                  (f) A current certificate issued by the Secretary of State of
         each Borrower's jurisdiction of incorporation, certifying that each
         Borrower is in compliance with all applicable organizational
         requirements of such jurisdiction.

                  (g) Evidence that each Borrower is duly licensed or qualified
         to transact business in the jurisdictions indicated on Schedule 5.1.

                  (h) An opinion of counsel to the Borrowers, addressed to the
         Lender and relating to issues as reasonably required by the Lender.

                  (i) Certificates of the insurance required hereunder, with all
         hazard insurance containing a lender's loss payable endorsement in the
         Lender's favor and with all liability insurance naming the Lender as an
         additional insured.

                  (j) Payment of the fees and commissions due through the date
         of the initial Advance under Section 2.3 and expenses incurred by the
         Lender through such date and required to be paid by the Borrowers under
         Section 9.6, including all legal expenses incurred through the date of
         this Agreement.

                  (k) Copies of the Merrill Lynch Loan Documents and all related
         documents, in form and substance reasonably satisfactory to the Lender,
         certified as being true, correct and complete by the Chief Executive
         Officer or Chief Financial Officer of the Parent.

                  (l) The conditions set forth in Section 4.2 shall have been
         satisfied.

                  (m) Such other documents as the Lender in its sole discretion
         may require.

                  Section 4.2 Conditions Precedent to All Advances . The
Lender's obligation to make each Advance shall be subject to the further
conditions precedent that on such date:

                  (a) the representations and warranties contained in Article V
         are correct on and as of the date of such Advance as though made on and
         as of such date, except to the extent that such representations and
         warranties relate solely to an earlier date; and

                  (b) no event has occurred and is continuing, or would result
         from such Advance which constitutes a Default or an Event of Default.

                                    ARTICLE V

                         Representations and Warranties

                  Each Borrower represents and warrants to the Lender as
follows:

                  Section 5.1 Corporate Existence and Power; Name; Chief
Executive Office; Inventory and Equipment Locations; Tax Identification Number .
Each Borrower is a corporation, duly organized, validly existing and in good
standing under the laws of the state of its incorporation as set forth on
Schedule 5.1 and is duly licensed or qualified to transact business in all
jurisdictions where the character of the property owned or leased or the nature
of the business transacted by it makes such licensing or qualification
necessary. Each Borrower has all requisite power and authority, corporate or
otherwise, to conduct its business, to own its properties and to execute and
deliver, and to perform all of its obligations under, the Loan Documents. During
its existence, each Borrower has done business solely under the names set forth
in Schedule 5.1 hereto. Each Borrower's chief executive office and principal
place of business is located at the address set forth in Schedule 5.1 hereto,
and all of each Borrower's records relating to its business or the Collateral
are kept at that location. All Inventory and Equipment is located at that
location or at one of the other locations set forth in Schedule 5.1 hereto. Each
Borrower's tax identification number is correctly set forth in Schedule 5.1
hereto.

                                       11
<PAGE>   15

                  Section 5.2 Authorization of Borrowing; No Conflict as to Law
or Agreements . The execution, delivery and performance by each Borrower of the
Loan Documents and the borrowings from time to time hereunder have been duly
authorized by all necessary corporate action and do not and will not (i) require
any consent or approval of any Borrower's stockholders; (ii) require any
authorization, consent or approval by, or registration, declaration or filing
with, or notice to, any governmental department, commission, board, bureau,
agency or instrumentality, domestic or foreign, or any third party, except such
authorization, consent, approval, registration, declaration, filing or notice as
has been obtained, accomplished or given prior to the date hereof; (iii) violate
any provision of any law, rule or regulation (including, without limitation,
Regulation T, U or X of the Board of Governors of the Federal Reserve System) or
of any order, writ, injunction or decree presently in effect having
applicability to any Borrower or of any Borrower's articles of incorporation or
bylaws; (iv) result in a breach of or constitute a default under any indenture
or loan or credit agreement or any other material agreement, lease or instrument
to which any Borrower is a party or by which it or its properties may be bound
or affected; or (v) result in, or require, the creation or imposition of any
mortgage, deed of trust, pledge, lien, security interest or other charge or
encumbrance of any nature (other than the Security Interest) upon or with
respect to any of the properties now owned or hereafter acquired by any
Borrower.

                  Section 5.3 Legal Agreements . This Agreement constitutes and,
upon due execution by each Borrower, the other Loan Documents will constitute
the legal, valid and binding obligations of each Borrower, enforceable against
each Borrower in accordance with their respective terms.

                  Section 5.4 Subsidiaries . Except as set forth in Schedule
5.4, no Borrower has any Subsidiaries.

                  Section 5.5 Financial Condition; No Adverse Change . The
Parent has heretofore furnished to the Lender audited financial statements of
the Parent for its fiscal year ended December 31, 1999 and unaudited financial
statements of the Parent for the fiscal year-to-date period ended March 31,
2000, and those statements fairly present the Parent's financial condition on a
consolidated basis on the dates thereof and the results of its operations and
cash flows for the periods then ended and were prepared in accordance with
generally accepted accounting principles. Since the date of the most recent
financial statements, there has been no material adverse change in the
Borrowers' business, properties or condition (financial or otherwise).

                  Section 5.6 Litigation . There are no actions, suits or
proceedings pending or, to any Borrower's knowledge, threatened against or
affecting the Borrowers or the properties of the Borrowers before any court or
governmental department, commission, board, bureau, agency or instrumentality,
domestic or foreign, which, if determined adversely to the Borrowers, would have
a material adverse effect on the financial condition, properties or operations
of the Borrowers.

                  Section 5.7 Regulation U . No Borrower is engaged in the
business of extending credit for the purpose of purchasing or carrying margin
stock (within the meaning of Regulation U of the Board of Governors of the
Federal Reserve System), and no part of the proceeds of any Advance will be used
to purchase or carry any margin stock or to extend credit to others for the
purpose of purchasing or carrying any margin stock.

                  Section 5.8 Taxes . Each Borrower has paid or caused to be
paid to the proper authorities when due all federal, state and local taxes
required to be withheld by it. Each Borrower has filed all federal, state and
local tax returns which to the knowledge of the officers of any Borrower are
required to be filed, and each Borrower has paid or caused to be paid to the
respective taxing authorities all taxes as shown on said returns or on any
assessment received by any of them to the extent such taxes have become due.

                  Section 5.9 Titles and Liens . Each Borrower has good and
absolute title to all Collateral described in the collateral reports provided to
the Lender and all other Collateral, properties and assets reflected in the
latest financial statements referred to in Section 5.5 and all proceeds thereof,
free and clear of all mortgages, security interests, liens and encumbrances,
except for Permitted Liens. No financing statement naming any Borrower as debtor
is on file in any office except to perfect only Permitted Liens.

                                       12
<PAGE>   16

                  Section 5.10 Plans . Except as disclosed to the Lender in
writing prior to the date hereof, no Borrower nor any of its Affiliates
maintains or has maintained or has contributed to any Plan or any
"multi-employer plan" as defined in ERISA. No Borrower nor any Affiliate has
received any notice or has any knowledge to the effect that it is not in full
compliance with any of the requirements of ERISA. No Reportable Event or other
fact or circumstance which may have an adverse effect on the Plan's tax
qualified status exists in connection with any Plan. No Borrower nor any of its
Affiliates has:

                  (a) Any accumulated funding deficiency within the meaning of
         ERISA; or

                  (b) Any liability or knows of any fact or circumstances which
         could result in any liability to the Pension Benefit Guaranty
         Corporation, the Internal Revenue Service, the Department of Labor or
         any participant in connection with any Plan (other than accrued
         benefits which or which may become payable to participants or
         beneficiaries of any such Plan).

                  Section 5.11 Default . Each Borrower is in compliance with all
provisions of all agreements, instruments, decrees and orders to which it is a
party or by which it or its property is bound or affected, the breach or default
of which could reasonably be expected to have a material adverse effect on the
Borrowers' financial condition, properties or operations.

                  Section 5.12 Environmental Matters .

                  (a) Definitions. As used in this Agreement, the following
         terms shall have the following meanings:

                           (i) "Environmental Law" means any federal, state,
                  local or other governmental statute, regulation, law or
                  ordinance dealing with the protection of human health and the
                  environment.

                           (ii) "Hazardous Substances" means pollutants,
                  contaminants, hazardous substances, hazardous wastes,
                  petroleum and fractions thereof, and all other chemicals,
                  wastes, substances and materials listed in, regulated by or
                  identified in any Environmental Law.

                  (b) To each Borrower's best knowledge, there are not present
         in, on or under the Premises any Hazardous Substances in such form or
         quantity as to create any liability or obligation for any Borrower or
         the Lender under common law of any jurisdiction or under any
         Environmental Law, and no Borrower has any knowledge that any Hazardous
         Substances have ever been stored, buried, spilled, leaked, discharged,
         emitted or released in, on or under the Premises in such a way as to
         create any such liability.

                  (c) To each Borrower's best knowledge, no Borrower has
         disposed of Hazardous Substances in such a manner as to create any
         liability under any Environmental Law.

                  (d) To each Borrower's knowledge, there are not and there
         never have been any requests, claims, notices, investigations, demands,
         administrative proceedings, hearings or litigation, relating in any way
         to the Premises or any Borrower, alleging liability under, violation
         of, or noncompliance with any Environmental Law or any license, permit
         or other authorization issued pursuant thereto. To each Borrower's best
         knowledge, no such matter is threatened or impending.

                  (e) To each Borrower's best knowledge, each Borrower's
         businesses are and have in the past always been conducted in accordance
         with all Environmental Laws and all licenses, permits and other
         authorizations required pursuant to any Environmental Law and necessary
         for the lawful and efficient operation of such businesses are in the
         relevant Borrower's possession and are in full force and effect. No
         permit required under any Environmental Law is scheduled to expire
         within 12 months and there is no threat that any such permit will be
         withdrawn, terminated, limited or materially changed.

                                       13
<PAGE>   17

                  (f) To each Borrower's best knowledge, the Premises are not
         and never have been listed on the National Priorities List, the
         Comprehensive Environmental Response, Compensation and Liability
         Information System or any similar federal, state or local list,
         schedule, log, inventory or database.

                  (g) Each Borrower has delivered to Lender all environmental
         assessments, audits, reports, permits, licenses and other documents of
         which such Borrower is aware describing or relating in any way to the
         Premises or such Borrower's businesses.

                  Section 5.13 Submissions to Lender . All financial and other
information provided to the Lender by or on behalf of the Borrowers in
connection with the Borrowers' request for the Credit Facility contemplated
hereby is true and correct in all material respects and, as to projections,
valuations or pro forma financial statements, presents a good faith opinion as
to such projections, valuations and pro forma condition and results.

                  Section 5.14 Financing Statements . Each Borrower has provided
to the Lender signed financing statements sufficient when filed to perfect the
Security Interest created by the Security Documents. When such financing
statements are filed in the offices noted therein, the Lender will have a valid
and perfected security interest in the Collateral that is capable of being
perfected by filing financing statements. None of the Collateral covered by the
Security Documents is or will become a fixture on real estate, unless a
sufficient fixture filing is in effect with respect thereto.

                  Section 5.15 Rights to Payment . Each right to payment and
each instrument, document, chattel paper and other agreement constituting or
evidencing Collateral covered by the Security Documents is (or, in the case of
all future Collateral, will be when arising or issued) the valid, genuine and
legally enforceable obligation, and to the best knowledge of each Borrower,
subject to no defense, setoff or counterclaim, of the account debtor or other
obligor named therein or in any Borrower's records pertaining thereto as being
obligated to pay such obligation.

                  Section 5.16 Financial Solvency . Both before and after giving
effect to the transactions contemplated in the Loan Documents, no Borrower:

                  (a) was or will be insolvent, as that term is used and defined
         in Section 101(32) of the United States Bankruptcy Code and Section 2
         of the Uniform Fraudulent Transfer Act;

                  (b) has unreasonably small capital or is engaged or about to
         engage in a business or a transaction for which any remaining assets of
         any Borrower or such Affiliate are unreasonably small;

                  (c) by executing, delivering or performing its obligations
         under the Loan Documents or other documents to which it is a party or
         by taking any action with respect thereto, intends to, nor believes
         that it will, incur debts beyond its ability to pay them as they
         mature;

                  (d) by executing, delivering or performing its obligations
         under the Loan Documents or other documents to which it is a party or
         by taking any action with respect thereto, intends to hinder, delay or
         defraud either its present or future creditors; and

                  (e) at this time contemplates filing a petition in bankruptcy
         or for an arrangement or reorganization or similar proceeding under any
         law any jurisdiction, nor, to the best knowledge of each Borrower, is
         the subject of any actual, pending or threatened bankruptcy, insolvency
         or similar proceedings under any law of any jurisdiction.

                  Section 5.17 Acquisitions. All of any Borrower's acquisitions
of all or substantially of the assets or stock of another entity since the
formation of such Borrower are as set forth on Schedule 5.17. Each of such
entities acquired in a stock acquisition, as set forth on Schedule 5.17, was
acquired by the relevant Borrower, was merged into such Borrower and no longer
exists as a legal entity.

                                       14
<PAGE>   18

                  Section 5.18 Merrill Lynch Loan Documents. Neither Parent nor
PentaStar Corporation recognizes, for GAAP reporting purposes, revenues on
payments from, or rights to, the Residual Pool (as defined in the Merril Lynch
Credit Agreement) until such revenues have been received from Ameritech. Neither
Parent nor PentaStar Corporation does or will account for such Residual Pool
receivables or rights on its balance sheet as Accounts or Receivables. No
Borrower (i) has any account with, (ii) has given, or has instructed any other
person to give, any cash, credit, deposits, accounts, financial assets,
investment property, securities or any other property of any Borrower to, or
(iii) is aware that any such cash, credit, deposits, accounts, financial assets,
investment property, securities or any other property of any Borrower is in
transit to or in the possession, custody or control of, MLBFS, MLPF&S or any
agent, bailee, or affiliate of MLBFS or MLPF&S (as such terms are defined in the
Merrill Lynch Credit Agreement), other than the establishment of the WCMA
Account (as defined in the Merrill Lynch Credit Agreement) in existence on the
date hereof and any payments to such WCMA Account that are permitted by Section
6.14 hereof. The only service that any Borrower has applied for in connection
with such WCMA Account is the "WCMA Commercial Line of Credit," as described in
the WCMA Agreement (which term is defined in the Merrill Lynch Credit
Agreement), applied for by PentaStar Corporation. For the avoidance of doubt, no
Borrower has established or has any "Securities Account", as described in such
WCMA Agreement.

                                   ARTICLE VI

                        Borrowers' Affirmative Covenants

                  So long as the Obligations shall remain unpaid, or the Credit
Facility shall remain outstanding, each Borrower will comply with the following
requirements, unless the Lender shall otherwise consent in writing:

                  Section 6.1 Reporting Requirements . Parent will deliver, or
cause to be delivered, to the Lender each of the following, which shall be in
form and detail acceptable to the Lender:

                  (a) as soon as available, and in any event before the earlier
         of (i) 90 days after the end of each fiscal year of the Parent and (ii)
         the date of the filing of the Parent's Annual Report on Form 10-K with
         the Securities and Exchange Commission, Parent's audited financial
         statements with the unqualified opinion of independent certified public
         accountants selected by the Parent and reasonably acceptable to the
         Lender, which annual financial statements shall include Parent's
         balance sheet as at the end of such fiscal year and the related
         statements of Parent's income, retained earnings and cash flows for the
         fiscal year then ended, prepared on a consolidated basis, and, if
         Lender so requests in writing, on a consolidating basis, to include all
         Subsidiaries of the Parent, all in reasonable detail and prepared in
         accordance with GAAP, together with (i) copies of all management
         letters prepared by such accountants; (ii) a report signed by such
         accountants stating that in making the investigations necessary for
         said opinion they obtained no knowledge, except as specifically stated,
         of any Default or Event of Default hereunder; and (iii) a certificate
         (substantially in the form of Exhibit B hereto) from Parent's chief
         financial officer stating that such financial statements have been
         prepared in accordance with GAAP (or how such financial statements vary
         from GAAP) and whether or not such officer has knowledge of the
         occurrence of any Default or Event of Default hereunder and, if so,
         stating in reasonable detail the facts with respect thereto, together
         with all relevant facts in reasonable detail to evidence, and the
         computations as to, whether or not the Parent is in compliance with the
         requirements set forth in Sections 6.11 and 6.12, with all such details
         and calculations as the Lender may require in connection therewith.

                  (b) as soon as available, and in any event before the earlier
         of (i) 45 days after the end of each quarter (except the last quarter)
         of the Parent and (ii) the date of the filing of the Parent's 10-Q with
         the Securities and Exchange Commission, the Parent's unaudited
         financial statements, which quarterly financial statements shall
         include the Parent's balance sheet as at the end of such quarter and
         the related statements of Parent's income, retained earnings and cash
         flows for the quarter then ended, prepared on a consolidated basis,
         and, if Lender so requests in writing, on a consolidating basis, to
         include all Subsidiaries of Parent, all in reasonable detail and
         prepared in accordance with GAAP, together with a certificate
         (substantially in the form of Exhibit B hereto) from Parent's chief
         financial officer stating that such financial statements have been
         prepared in accordance with GAAP (or how such financial statements vary
         from GAAP) and whether or not such officer has knowledge of the
         occurrence of any Default or Event

                                       15
<PAGE>   19

         of Default hereunder and, if so, stating in reasonable detail the facts
         with respect thereto, together with all relevant facts in reasonable
         detail to evidence, and the computations as to, whether or not the
         Parent is in compliance with the requirements set forth in Sections
         6.11 and 6.12, with all such details and calculations as the Lender may
         require in connection therewith;

                  (c) as soon as available and in any event within 30 days after
         the end of each month, an unaudited/internal balance sheet and
         statements of income and retained earnings of the Parent as at the end
         of and for such month and for the year to date period then ended,
         prepared on a consolidated basis, and, if Lender so requests in
         writing, on a consolidating basis, in reasonable detail and, beginning
         in November 2000, stating in comparative form the figures for the
         corresponding date and periods in the previous year, all prepared in
         accordance with GAAP, subject to year-end audit adjustments;

                  (d) within 30 days after the end of each month or more
         frequently if the Lender so requires, agings of the Parent's
         consolidated Receivables (broken down by Borrower) and a calculation of
         each Borrower's Accounts, Net Accounts and Eligible Accounts as at the
         end of such month or shorter time period;

                  (e) at least 30 days before the beginning of each fiscal year
         of the Parent, the projected balance sheets and income statements for
         each month of such year, each in reasonable detail, representing the
         Parent's good faith projections and certified by the Parent's chief
         financial officer as being the most accurate projections available and
         identical to the projections used by the Parent for internal planning
         purposes, together with such supporting schedules and information as
         the Lender may in its reasonable discretion require;

                  (f) immediately after the commencement thereof, notice in
         writing of all litigation and of all proceedings before any
         governmental or regulatory agency affecting any Borrower of the type
         described in Section 5.12 or which seek a monetary recovery against any
         Borrower in excess of $100,000;

                  (g) as promptly as practicable (but in any event not later
         than five business days) after an officer of any Borrower obtains
         knowledge of the occurrence of any breach, default or event of default
         under any Security Document or any event which constitutes a Default or
         Event of Default hereunder, notice of such occurrence, together with a
         detailed statement by a responsible officer of the Parent of the steps
         being taken by the Parent to cure the effect of such breach, default or
         event;

                  (h) as soon as possible and in any event within 30 days after
         any Borrower knows or has reason to know that any Reportable Event with
         respect to any Plan has occurred, the statement of the Parent's chief
         financial officer setting forth details as to such Reportable Event and
         the action which the Parent proposes to take with respect thereto,
         together with a copy of the notice of such Reportable Event to the
         Pension Benefit Guaranty Corporation;

                  (i) as soon as possible, and in any event within 10 days after
         any Borrower fails to make any quarterly contribution required with
         respect to any Plan under Section 412(m) of the Internal Revenue Code
         of 1986, as amended, the statement of the Parent's chief financial
         officer setting forth details as to such failure and the action which
         the Parent proposes to take with respect thereto, together with a copy
         of any notice of such failure required to be provided to the Pension
         Benefit Guaranty Corporation;

                  (j) promptly upon knowledge thereof, notice of (i) any
         disputes or claims by any Borrower's customers exceeding $100,000
         individually or $500,000 in the aggregate during any fiscal year, (ii)
         any change in the persons constituting the Parent's Chief Executive
         Officer or Chief Operating Officer or (iii) either Craig Zoellner or
         Richard Tyler ceasing to be on the Parent's board of directors or
         submitting a letter of resignation therefrom;

                  (k) promptly upon any Borrower's knowledge thereof, notice of
         any material loss of or material damage to any material item of
         Collateral or of any substantial adverse change in any material item of
         Collateral or the prospect of payment of any material Receivable;

                                       16
<PAGE>   20

                  (l) promptly upon their distribution, copies of all financial
         statements, reports and proxy statements which the Parent shall have
         sent to its stockholders;

                  (m) promptly after the sending or filing thereof, copies of
         all regular and periodic reports which the Parent shall file with the
         Securities and Exchange Commission or any national securities exchange;

                  (n) promptly upon any Borrower's knowledge thereof, notice of
         any Borrower's violation of any law, rule or regulation, the
         non-compliance with which could reasonably be expected to materially
         and adversely affect the Borrowers' business or its financial
         condition; and

                  (o) a monthly updated Borrowing Base reconciliation report.

                  Section 6.2 Books and Records; Inspection and Examination .
Each Borrower will keep accurate books of record and account for itself
pertaining to the Collateral and pertaining to such Borrower's business and
financial condition and such other matters as the Lender may from time to time
request in which true and complete entries will be made in accordance with GAAP
and, upon the Lender's request, will permit any officer, employee, attorney or
accountant for the Lender to audit, review, make extracts from or copy any and
all corporate and financial books and records of the Borrowers at all times
during ordinary business hours, to send and discuss with account debtors and
other obligors requests for verification of amounts owed to the Borrowers, and
to discuss the Borrowers' affairs with any of the Borrowers' directors,
officers, employees or agents. The Borrowers will permit the Lender, or its
employees, accountants, attorneys or agents, to examine and inspect any
Collateral or any other property of any Borrower at any time during ordinary
business hours. Without limiting the generality of the foregoing, Borrowers
shall cooperate with the Auditor in connection with the Auditor's audits of the
Borrowers' Accounts from time to time.

                  Section 6.3 Account Verification . The Lender may at any time
and from time to time send or require the Borrowers to send requests for
verification of accounts or notices of assignment to account debtors and other
obligors. The Lender may also at any time and from time to time telephone
account debtors and other obligors to verify accounts.

                  Section 6.4 Compliance with Laws .

                  (a) Each Borrower will (i) comply with the requirements of
         applicable laws and regulations, the non-compliance with which would
         materially and adversely affect the Borrowers' business or the
         Borrowers' financial condition and (ii) use and keep the Collateral,
         and require that others use and keep the Collateral, only for lawful
         purposes, without violation of any federal, state or local law, statute
         or ordinance.

                  (b) Without limiting the foregoing undertakings, each Borrower
         specifically agrees that it will comply with all applicable
         Environmental Laws and obtain and comply with all permits, licenses and
         similar approvals required by any Environmental Laws, and will not
         generate, use, transport, treat, store or dispose of any Hazardous
         Substances in such a manner as to create any liability or obligation
         under the common law of any jurisdiction or any Environmental Law.

                  Section 6.5 Payment of Taxes and Other Claims . Each Borrower
will pay or discharge, when due, (a) all taxes, assessments and governmental
charges levied or imposed upon it or upon its income or profits, upon any
properties belonging to it (including, without limitation, the Collateral) or
upon or against the creation, perfection or continuance of the Security
Interest, prior to the date on which penalties attach thereto, (b) all federal,
state and local taxes required to be withheld by it, and (c) all lawful claims
for labor, materials and supplies which, if unpaid, might by law become a lien
or charge upon any properties of any Borrower; provided, that no Borrower shall
be required to pay any such tax, assessment, charge or claim whose amount,
applicability or validity is being contested in good faith by appropriate
proceedings diligently pursued and for which proper reserves have been made in
accordance with GAAP and so long as no Lien shall result therefrom.

                                       17
<PAGE>   21

                  Section 6.6 Maintenance of Properties .

                  (a) Each Borrower will keep and maintain the Collateral and
         all of its other properties necessary or useful in its business in
         reasonably good condition, repair and working order (normal wear and
         tear excepted) and will from time to time replace or repair any worn,
         defective or broken parts; provided, however, that nothing in this
         Section 6.6 shall prevent any Borrower from discontinuing the operation
         and maintenance of any of its properties if such discontinuance is
         desirable in the conduct of the Borrowers' businesses and not
         disadvantageous in any material respect to the Lender.

                  (b) Each Borrower will defend the Collateral against all
         claims or demands of all persons (other than the Lender) claiming the
         Collateral or any interest therein.

                  (c) Each Borrower will keep all Collateral free and clear of
         all Liens except Permitted Liens.

                  Section 6.7 Insurance . Each Borrower will obtain and at all
times maintain insurance with insurers believed by the Borrowers to be
responsible and reputable, in such amounts and against such risks as may from
time to time reasonably be required by the Lender, but in all events in such
amounts and against such risks as is usually carried by companies engaged in
similar business and owning similar properties in the same general areas in
which the Borrowers operate. Without limiting the generality of the foregoing,
each Borrower will at all times keep all tangible Collateral insured against
risks of fire (including so-called extended coverage), theft, collision (for
Collateral consisting of motor vehicles) and such other risks and in such
amounts as the Lender may reasonably request, with any loss payable to the
Lender to the extent of its interest, and all policies of such insurance shall
contain a lender's loss payable endorsement for the Lender's benefit reasonably
acceptable to the Lender. All policies of liability insurance required hereunder
shall name the Lender as an additional insured.

                  Section 6.8 Preservation of Existence . Each Borrower will
preserve and maintain its existence and all of its rights, privileges and
franchises necessary or desirable in the normal conduct of its business and
shall conduct its business in an orderly, efficient and regular manner.

                  Section 6.9 Delivery of Instruments, etc. Upon request by the
Lender, each Borrower will promptly deliver to the Lender in pledge all
instruments, documents and chattel papers constituting Collateral, duly endorsed
or assigned by the Borrowers.

                  Section 6.10 Performance by the Lender . If any Borrower at
any time fails to perform or observe any of the foregoing covenants contained in
this Article VI or elsewhere herein, and if such failure shall continue for a
period of ten calendar days after the Lender gives any Borrower written notice
thereof (or in the case of the agreements contained in Sections 6.5and 6.7,
immediately upon the occurrence of such failure, without notice or lapse of
time), the Lender may, but need not, perform or observe such covenant on behalf
and in the name, place and stead of the Borrowers (or, at the Lender's option,
in the Lender's name) and may, but need not, take any and all other actions
which the Lender may reasonably deem necessary to cure or correct such failure
(including, without limitation, the payment of taxes, the satisfaction of
security interests, liens or encumbrances, the performance of obligations owed
to account debtors or other obligors, the procurement and maintenance of
insurance, the execution of assignments, security agreements and financing
statements, and the endorsement of instruments); and the Borrowers shall
thereupon pay to the Lender on demand the amount of all monies expended and all
reasonable costs and expenses (including reasonable attorneys' fees and legal
expenses) incurred by the Lender in connection with or as a result of the
performance or observance of such agreements or the taking of such action by the
Lender, together with interest thereon from the date expended or incurred at the
then current rate of interest applicable to the Note. To facilitate the Lender's
performance or observance of such covenants of the Borrowers, the Borrowers
hereby irrevocably appoints the Lender, or the Lender's delegate, acting alone,
as the Borrowers' attorney in fact (which appointment is coupled with an
interest) with the right (but not the duty) from time to time to create,
prepare, complete, execute, deliver, endorse or file in the name and on behalf
of the Borrowers any and all instruments, documents, assignments, security
agreements, financing statements, applications for insurance and other
agreements and writings required to be obtained, executed, delivered or endorsed
by the Borrowers under this Section 6.10.

                                       18
<PAGE>   22

                  Section 6.11 Minimum Current Ratio . Parent will maintain its
Current Ratio on a consolidated basis, determined as at the end of each quarter,
at or above 1.5 to 1.00.

                  Section 6.12 Total Leverage Ratio . The Parent shall not
permit the Total Leverage Ratio, determined quarterly, to exceed 1.5. For this
purpose, "Total Leverage Ratio" means, on any date of determination, the ratio
of (a) Parent's consolidated total Funded Debt on such date (excluding the
Merrill Lynch Long Term Debt) to (b) Parent's consolidated EBITDA for the most
recently completed four fiscal quarters, provided that for purposes of this
calculation, EBITDA (i) shall be calculated as if all assets acquired (including
without limitation acquisitions of stock) on any date during the twelve month
period of determination were acquired on the first day in such twelve month
period of determination, and all assets sold (including without limitation
dispositions of stock) on any date during the twelve month period of
determination were sold on the first day in such twelve month period of
determination, in each case with costs adjusted to the levels that any Borrower
will incur, and (ii) shall include corporate overhead annualized based on the
level incurred in the most recent quarter.

                  Section 6.13 Lien Releases. The Borrowers shall, within 30
days of the date hereof, cause to be terminated all Liens and all financial
statements that do not constitute or represent Liens permitted by Section 7.1.

                  Section 6.14 Merrill Lynch Loan Documents. (a) Each Borrower
agrees that no Borrower (i) will establish or permit to exist any account with,
(ii) will give, or will instruct any other person to give, any cash, credit,
deposits, accounts, financial assets, investment property, securities or any
other property of any Borrower to, or (iii) will permit any such cash, credit,
deposits, accounts, financial assets, investment property, securities or any
other property of any Borrower to be in transit to or in the possession, custody
or control of, MLBFS, MLPF&S or any agent, bailee, or affiliate of MLBFS or
MLPF&S (as such terms are defined in the Merrill Lynch Credit Agreement), other
than the establishment of the WCMA Account (as defined in the Merrill Lynch
Credit Agreement) in existence on the date hereof and any payments to such WCMA
Account that are permitted by clause (b) of this Section 6.14.

                  (b) PentaStar Corporation further agrees that it shall not pay
any amounts under or pursuant to the Merrill Lynch Credit Agreement, including
without limitation any payments into the WCMA Account, except for regularly
scheduled payments of principal and interest thereunder pursuant to Section 3.5
and 3.6 thereof and fees, costs and expenses specifically required to be paid
thereunder. PentaStar Corporation shall not prepay any amounts under the Merrill
Lynch Credit Agreement (including without limitation pursuant to Section 3.11
thereof) nor request Subsequent WCMA Loans (as defined in the Merrill Lynch
Credit Agreement) unless in either case (i) the Lender has given its prior
written consent thereto or (ii) the outstanding balance of this Credit Facility
at the time of such prepayment or request is zero and no request for an Advance
hereunder is currently pending (other than such Subsequent WCMA Loans made
automatically to pay accrued interest in accordance with the terms of the
Merrill Lynch Credit Agreement).

                  (c) PentaStar Corporation further agrees that, upon written
request of Lender, it shall provide the Lender with (i) copies of all
information relating to the Residual Pool that it has provided to Merrill Lynch
Business Financial Services Inc. pursuant to Section 4.2(a)(iii) of the Merrill
Lynch Credit Agreement and (ii) notice of any additional contribution of
collateral to Merrill Lunch Business Financial Services Inc. pursuant to Section
4.3(i)(ii) of the Merrill Lynch Credit Agreement.

                  (d) Other than the WCMA Commercial Line of Credit referred to
in Section 5.18, which is evidenced by the Merrill Lynch Loan Documents, no
Borrower will apply for or establish any other financial service or other
arrangement with MLBFS or MLPF&S (as such terms are defined in the Merrill Lynch
Credit Agreement) or any affiliate thereof.

                  Section 6.15 Lock Box Arrangement. Upon request of the Lender,
Borrowers agree that they shall enter into a lockbox arrangement with Lender in
accordance with Lenders' customary procedures and documentation, in a manner
acceptable to the Lender.

                                       19
<PAGE>   23

                                   ARTICLE VII

                               Negative Covenants

                  So long as the Obligations shall remain unpaid, or the Credit
Facility shall remain outstanding, each Borrower agrees that, without the
Lender's prior written consent:

                  Section 7.1 Liens . No Borrower will create, incur or suffer
to exist any mortgage, deed of trust, pledge, lien, security interest,
assignment or transfer upon or of any of its assets (collectively, "Liens"), now
owned or hereafter acquired, to secure any indebtedness; excluding, however,
from the operation of the foregoing, the following (collectively, "Permitted
Liens"):

                  (a) in the case of any Borrower's property which is not
         Collateral, covenants, restrictions, rights, easements and minor
         irregularities in title which do not materially interfere with the
         Borrowers' businesses or operations as presently conducted;

                  (b) mortgages, deeds of trust, pledges, liens, security
         interests and assignments in existence on the date hereof and listed in
         Schedule 7.1 hereto, securing indebtedness for borrowed money permitted
         under Section 7.2;

                  (c) the Security Interest and liens and security interests
         created by the Security Documents;

                  (d) the Merrill Lynch Lien; and

                  (e) purchase money security interests relating to the
         acquisition of machinery and equipment of the Borrower not exceeding
         the lesser of cost or fair market value thereof, not exceeding $100,000
         in the aggregate during the period beginning on the date hereof until
         payment in full of the Obligations and so long as no Default or Event
         of Default is then in existence and none would exist immediately after
         such acquisition.

                  Section 7.2 Indebtedness . No Borrower will incur, create,
assume or permit to exist any Debt, except:

                  (a) indebtedness arising hereunder;

                  (b) indebtedness of any Borrower in existence on the date
         hereof, as described in, and in amounts no greater than as listed in,
         Schedule 7.2 hereto;

                  (c) the Merrill Lynch Long Term Debt; and

                  (d) indebtedness relating to liens permitted in accordance
         with Section 7.1(d).

                  Section 7.3 Guaranties . No Borrower will assume, guarantee,
endorse or otherwise become directly or contingently liable in connection with
any obligations of any other Person, except:

                  (a) the endorsement of negotiable instruments by any Borrower
         for deposit or collection or similar transactions in the ordinary
         course of business; and

                  (b) guaranties, endorsements and other direct or contingent
         liabilities in connection with the obligations of other Persons, in
         existence on the date hereof and listed in Schedule 7.2 hereto.

                                       20
<PAGE>   24

                  Section 7.4 Investments and Subsidiaries .

                  (a) No Borrower will purchase or hold beneficially any stock
         or other securities or evidences of indebtedness of, make or permit to
         exist any loans or advances to, or make any investment or acquire any
         interest whatsoever in, any other Person, including specifically but
         without limitation any partnership or joint venture, except:

                           (i) investments in direct obligations of the United
                  States of America or any agency or instrumentality thereof
                  whose obligations constitute full faith and credit obligations
                  of the United States of America having a maturity of one year
                  or less, commercial paper issued by U.S. corporations rated
                  "A-1" or "A-2" by Standard & Poors Corporation or "P-1" or
                  "P-2" by Moody's Investors Service or certificates of deposit
                  or bankers' acceptances having a maturity of one year or less
                  issued by members of the Federal Reserve System having
                  deposits in excess of $100,000,000 (which certificates of
                  deposit or bankers' acceptances are fully insured by the
                  Federal Deposit Insurance Corporation); and

                           (ii) investments constituting "Permitted
                  Acquisitions" permitted by Section 7.7.

                           (iii) investments made by the Parent, or a wholly
                  owned Subsidiary of the Parent that is or becomes a Borrower
                  under this Agreement, in Persons operating in the same line of
                  business as the Parent, the sum of which investments in the
                  aggregate for all Borrowers does not exceed $500,000 at any
                  time outstanding.

                  (b) No Borrower will create or permit to exist any Subsidiary
         other than (i) the Subsidiaries in existence on the date hereof and
         listed on Schedule 5.4 and (ii) Subsidiaries constituting "Permitted
         Acquisitions" permitted by Section 7.7.

                  Section 7.5 Dividends . Except as set forth below, no Borrower
will declare or pay any dividends (other than dividends payable solely in such
Borrower's capital stock) on any class of its stock or make any payment on
account of the purchase, redemption or other retirement of any shares of such
stock or make any distribution in respect thereof, either directly or
indirectly.

                  Section 7.6 Sale or Transfer of Assets; Suspension of Business
Operations . No Borrower will sell, lease, assign, transfer or otherwise dispose
of (i) the stock of any Subsidiary, (ii) all or a substantial part of its
assets, or (iii) any Collateral or any interest therein (whether in one
transaction or in a series of transactions) to any other Person other than the
sale of Inventory in the ordinary course of business and will not liquidate,
dissolve or suspend business operations. No Borrower will in any manner transfer
any property without prior or present receipt of full and adequate
consideration.

                  Section 7.7 Consolidation and Merger; Asset Acquisitions . No
Borrower will consolidate with or merge into any Person, or permit any other
Person to merge into it, or acquire all or substantially all the assets of any
other Person except with Lender's prior written approval, except that (a) the
Parent may consummate Permitted Acquisitions so long as in each case (1) there
exists no Default or Event of Default both before and after giving effect to any
such acquisition, (2) the Lender shall have received prior written notice
thereof and (3) the Parent shall have confirmed in writing to the Lender that
(I) the proposed acquisition conforms to the definition of Permitted Acquisition
and (II) the Parent's projections made in good faith after giving effect to the
proposed acquisition evidence pro forma compliance with the terms of Sections
6.11 and 6.12 and (b) any Borrower may merge with and into the Parent so long as
the Parent is the surviving entity.

                  Section 7.8 Sale and Leaseback . No Borrower will enter into
any arrangement, directly or indirectly, with any other Person whereby any
Borrower shall sell or transfer any real or personal property, whether now owned
or hereafter acquired, and then or thereafter rent or lease as lessee such
property or any part thereof or any other property which such Borrower intends
to use for substantially the same purpose or purposes as the property being sold
or transferred.

                                       21
<PAGE>   25

                  Section 7.9 Restrictions on Nature of Business . No Borrower
will engage in any line of business materially different from that presently
engaged in by the Borrowers and will not purchase, lease or otherwise acquire
assets not related to its business.

                  Section 7.10 Accounting . No Borrower will adopt any material
change in accounting principles other than as required by GAAP. No Borrower will
adopt, permit or consent to any change in its fiscal year.

                  Section 7.11 Defined Benefit Pension Plans . No Borrower will
adopt, create, assume or become a party to any defined benefit pension plan,
unless disclosed to the Lender pursuant to Section 5.10.

                  Section 7.12 Other Defaults . No Borrower will permit any
breach, default or event of default to occur under any note, loan agreement,
indenture, lease, mortgage, contract for deed, security agreement or other
contractual obligation binding upon any Borrower except for any such breach,
default or event of default which would not reasonably be expected to have a
material adverse effect on the Borrowers' business or the Borrowers' financial
condition.

                  Section 7.13 Place of Business; Name . No Borrower will
transfer its chief executive office or principal place of business. No Borrower
will move, relocate, close or sell any other material business location without
providing Lender prior written notice thereof. No Borrower will permit any
tangible Collateral or any records pertaining to the Collateral to be located in
any state or area in which, in the event of such location, a financing statement
covering such Collateral would be required to be, but has not in fact been,
filed in order to perfect the Security Interest. No Borrower will change its
name.

                  Section 7.14 Organizational Documents . No Borrower will amend
its certificate of incorporation, articles of incorporation or bylaws.

                                  ARTICLE VIII

                     Events of Default, Rights and Remedies

                  Section 8.1 Events of Default . "Event of Default", wherever
used herein, means any one of the following events:

                  (a) default in the payment of the Obligations when they become
         due and payable;

                  (b) default in the payment of any fees, commissions, costs or
         expenses required to be paid by any Borrower under this Agreement;

                  (c) default in the performance, or breach, of any covenant or
         agreement of any Borrower contained in this Agreement;

                  (d) any Borrower shall be or become insolvent, or admit in
         writing its inability to pay its debts as they mature, or make an
         assignment for the benefit of creditors; or any Borrower shall apply
         for or consent to the appointment of any receiver, trustee, or similar
         officer for it or for all or any substantial part of its or his
         property; or such receiver, trustee or similar officer shall be
         appointed without the application or consent of any Borrower, as the
         case may be; or any Borrower shall institute (by petition, application,
         answer, consent or otherwise) any bankruptcy, insolvency,
         reorganization, arrangement, readjustment of debt, dissolution,
         liquidation or similar proceeding relating to it under the laws of any
         jurisdiction; or any such proceeding shall be instituted (by petition,
         application or otherwise) against any Borrower; or any judgment, writ,
         warrant of attachment or execution or similar process shall be issued
         or levied against a substantial part of the property of any Borrower;

                  (e) a petition shall be filed by or against any Borrower under
         the United States Bankruptcy Code naming any Borrower as debtor;

                                       22
<PAGE>   26

                  (f) any representation or warranty made by any Borrower in
         this Agreement, or by any Borrower (or any of its officers) in any
         agreement, certificate, instrument or financial statement or other
         statement contemplated by or made or delivered pursuant to or in
         connection with this Agreement or any such guaranty shall prove to have
         been incorrect in any material respect when deemed to be effective;

                  (g) the rendering against any Borrower of a final judgment,
         decree or order for the payment of money in excess of $100,000 and the
         continuance of such judgment, decree or order unsatisfied and in effect
         for any period of 30 consecutive days without a stay of execution;

                  (h) any Reportable Event, which the Lender determines in good
         faith might constitute grounds for the termination of any Plan or for
         the appointment by the appropriate United States District Court of a
         trustee to administer any Plan, shall have occurred and be continuing
         30 days after written notice to such effect shall have been given to
         any Borrower by the Lender; or a trustee shall have been appointed by
         an appropriate United States District Court to administer any Plan; or
         the Pension Benefit Guaranty Corporation shall have instituted
         proceedings to terminate any Plan or to appoint a trustee to administer
         any Plan; or any Borrower shall have filed for a distress termination
         of any Plan under Title IV of ERISA; or any Borrower shall have failed
         to make any quarterly contribution required with respect to any Plan
         under Section 412(m) of the Internal Revenue Code of 1986, as amended,
         which the Lender determines in good faith may by itself, or in
         combination with any such failures that the Lender may determine are
         likely to occur in the future, result in the imposition of a Lien on
         any Borrower's assets in favor of the Plan;

                  (i) an event of default shall occur under any Security
         Document or under any other security agreement, mortgage, deed of
         trust, assignment or other instrument or agreement securing the
         obligations of any Borrower hereunder or under the Note;

                  (j) any Borrower shall liquidate, dissolve, terminate or
         suspend its business operations or otherwise fail to operate its
         business in the ordinary course, or sell all or substantially all of
         its assets (except for a sale or transfer of such assets to the
         Parent), without the Lender's prior written consent;

                  (k) any Borrower shall fail to pay, withhold, collect or remit
         any tax or tax deficiency when assessed or due (other than any tax
         deficiency which is being contested in good faith and by proper
         proceedings diligently pursued and for which it shall have set aside on
         its books adequate reserves therefor in accordance with GAAP, provided
         that no Lien shall result therefrom) or notice of any state or federal
         tax liens shall be filed or issued against such Borrower's property;

                  (l) default in the payment of any amount owed by any Borrower
         to the Lender other than any indebtedness arising hereunder; or

                  (m) Bace Investment LLC shall sell more than 50% of the stock
         it owns in the Parent as of the date hereof (such stock on the date
         hereof consisting of 1,674,800 shares of stock representing 33% of the
         issued and outstanding shares of stock of the Parent immediately prior
         to the acquisition by PentaStar Corporation of Telecomm Industries,
         Inc.), provided that in no event shall Bace Investment LLC cease to be
         the largest shareholder of the Parent.

                  Section 8.2 Rights and Remedies . Upon the occurrence and
during the continuance of an Event of Default, the Lender may exercise any or
all of the following rights and remedies:

                  (a) the Lender may, by notice to Parent, declare the
         Commitment to be terminated, whereupon the same shall forthwith
         terminate;

                  (b) the Lender may, by notice to Parent, declare the
         Obligations to be forthwith due and payable, whereupon all Obligations
         shall become and be forthwith due and payable, without presentment,
         notice of dishonor, protest or further notice of any kind, all of which
         the Borrowers hereby expressly waive;

                                       23
<PAGE>   27

                  (c) the Lender may, without notice to any Borrower and without
         further action, apply any and all money owing by the Lender to the
         Borrowers to the payment of the Obligations;

                  (d) the Lender may exercise and enforce any and all rights and
         remedies available upon default to a secured party under the UCC,
         including, without limitation, the right to take possession of
         Collateral, or any evidence thereof, proceeding without judicial
         process or by judicial process (without a prior hearing or notice
         thereof, which the Borrowers hereby expressly waive) and the right to
         sell, lease or otherwise dispose of any or all of the Collateral, and,
         in connection therewith, the Borrowers will on demand assemble the
         Collateral and make it available to the Lender at a place to be
         designated by the Lender which is reasonably convenient to both
         parties;

                  (e) the Lender may exercise and enforce its rights and
         remedies under the Loan Documents; and

                  (f) the Lender may exercise any other rights and remedies
         available to it by law or agreement.

Notwithstanding the foregoing, upon the occurrence of an Event of Default
described in subsections (d) or (e) of Section 8.1, the Obligations shall be
immediately due and payable automatically without presentment, demand, protest
or notice of any kind.

                  Section 8.3 Certain Notices . If notice to any Borrower of any
intended disposition of Collateral or any other intended action is required by
law in a particular instance, such notice shall be deemed commercially
reasonable if given (in the manner specified in Section 9.3) at least ten
calendar days before the date of intended disposition or other action.

                                   ARTICLE IX

                                  Miscellaneous

                  Section 9.1 No Waiver; Cumulative Remedies . No failure or
delay by the Lender in exercising any right, power or remedy under the Loan
Documents shall operate as a waiver thereof; nor shall any single or partial
exercise of any such right, power or remedy preclude any other or further
exercise thereof or the exercise of any other right, power or remedy under the
Loan Documents. The remedies provided in the Loan Documents are cumulative and
not exclusive of any remedies provided by law.

                  Section 9.2 Amendments, Etc. No amendment, modification,
termination or waiver of any provision of any Loan Document or consent to any
departure by any Borrower therefrom or any release of a Security Interest shall
be effective unless the same shall be in writing and signed by the Lender, and
then such waiver or consent shall be effective only in the specific instance and
for the specific purpose for which given. No notice to or demand on any Borrower
in any case shall entitle any Borrower to any other or further notice or demand
in similar or other circumstances.

                  Section 9.3 Addresses for Notices, Etc. Except as otherwise
expressly provided herein, all notices, requests, demands and other
communications provided for under the Loan Documents shall be in writing and
shall be (a) personally delivered, (b) sent by first class United States mail,
(c) sent by overnight courier of national reputation, or (d) transmitted by
telecopy, in each case addressed or telecopied to the party to whom notice is
being given at its address or telecopier number as set forth below:

                                       24
<PAGE>   28

                  If to any Borrower:

                  C/o PentaStar Communications, Inc.
                  1522 Blake Street, Denver, CO 80202
                  Telecopier:  303-825-4402
                  Telephone:  303-825-4400
                  Attn:  David L. Dunham

                  If to the Lender:

                  Wells Fargo Bank West, N.A.
                  1740 Broadway
                  Denver, Colorado  80274
                  MAC #C7301-031
                  Telecopier:  303/863-6670
                  Attention:  Lynn N. Hout

or, as to each party, at such other address or telecopier number as may
hereafter be designated by such party in a written notice to the other party
complying as to delivery with the terms of this Section. All such notices,
requests, demands and other communications shall be deemed to have been given on
(a) the date received if personally delivered, (b) when deposited in the mail if
delivered by mail, (c) the date sent if sent by overnight courier, or (d) the
date of transmission if delivered by telecopy, except that notices or requests
to the Lender pursuant to any of the provisions of Article II shall not be
effective until received by the Lender.

                  Section 9.4 Further Documents . Each Borrower will from time
to time execute and deliver or endorse any and all instruments, documents,
conveyances, assignments, security agreements, financing statements and other
agreements and writings that the Lender may reasonably request in order to
secure, protect, perfect or enforce the Security Interest or the Lender's rights
under the Loan Documents (but any failure to request or assure that any Borrower
executes, delivers or endorses any such item shall not affect or impair the
validity, sufficiency or enforceability of the Loan Documents and the Security
Interest, regardless of whether any such item was or was not executed, delivered
or endorsed in a similar context or on a prior occasion).

                  Section 9.5 Collateral . The Lender shall not be obligated to
preserve any rights any Borrower may have against prior parties, to realize on
the Collateral at all or in any particular manner or order or to apply any cash
proceeds of the Collateral in any particular order of application, except as
required by law.

                  Section 9.6 Costs and Expenses . The Borrowers agree to pay on
demand all costs and expenses, including (without limitation) reasonable
attorneys' fees, incurred by the Lender in connection with the Obligations, the
Loan Documents, and any other document or agreement related hereto or thereto,
and the transactions contemplated hereby, including without limitation all such
costs, expenses and fees incurred in connection with the negotiation,
preparation, execution, amendment, administration, performance, collection and
enforcement of the Obligations and all such documents and agreements and the
creation, perfection, protection, satisfaction, foreclosure or enforcement of
the Security Interest.

                  Section 9.7 Indemnity . In addition to the payment of expenses
pursuant to Section 9.6, the Borrowers shall indemnify and hold harmless the
Lender and persons or entities owned or controlled by or affiliated with the
Lender and its directors, officers, shareholders, partners, employees,
consultants and agents (herein individually called an "Indemnified Party," and
collectively called "Indemnified Parties") from and against, and reimburse and
pay Indemnified Parties with respect to, any and all claims, demands,
liabilities, losses, damages, causes of action, judgments, penalties, fees,
costs and expenses (including, without limitation, reasonable attorneys' fees,
court costs and legal expenses and reasonable consultants' and experts' fees and
expenses), of any and every kind or character, known or unknown, fixed or
contingent, that may be imposed upon, asserted against or incurred or paid by or
on behalf of any Indemnified Party on account of, in connection with, or arising
out of (a) any act performed or omitted to be performed by any Borrower
hereunder or the breach by any Borrower of, or failure by any Borrower to
perform any, warranty, representation, indemnity, covenant, agreement or
condition contained in

                                       25
<PAGE>   29

any of the Loan Documents, (b) any transaction, act, omission, event or
circumstance arising out of or in any way connected with the Collateral or any
Borrower's performance or obligation under any of the Loan Documents (to the
extent not arising out of any gross negligence or wilful misconduct of Lender),
(c) any Borrower's violation of or failure to comply with any statute, law,
rule, regulation or order now existing or hereafter occurring, including,
without limitation, environmental laws and statutes, laws, rules, regulations
and orders relating to pollutants, contaminants, wastes or hazardous, dangerous
or toxic substances, and (d) any Borrower's failure to pay any expense
associated with the Credit Facility. Any amount to be paid hereunder by any
Borrower to the Lender or for which any Borrower has indemnified an Indemnified
Party shall be a demand obligation owing by the Borrowers to the Lender and
shall bear interest at the Default Rate until paid, and shall constitute a part
of the Obligations and be indebtedness secured and evidenced by the Loan
Documents. If any investigative, judicial or administrative proceeding arising
from any of the foregoing is brought against any Indemnitee, upon such
Indemnitee's request, the Borrowers, or counsel designated by the Borrowers and
reasonably satisfactory to the Indemnitee, will resist and defend such action,
suit or proceeding to the extent and in the manner reasonably directed by the
Indemnitee, at the Borrowers' sole costs and expense. Each Indemnitee will use
its best efforts to cooperate in the defense of any such action, suit or
proceeding. If the foregoing undertaking to indemnify, defend and hold harmless
may be held to be unenforceable because it violates any law or public policy,
the Borrowers shall nevertheless make the maximum contribution to the payment
and satisfaction of each of the Indemnified Liabilities which is permissible
under applicable law. The Borrowers' obligation under this Section 9.7 shall
survive the termination of this Agreement, any foreclosure of the liens and
security interests created by the Loan Documents or conveyance in lieu of
foreclosure, the repayment and performance of the Loan, the discharge of the
Borrowers' other obligations hereunder and the discharge and release of the
liens and security interest created by the other Loan Documents.

                  Section 9.8 Participants . The Lender and its participants, if
any, are not partners or joint venturers, and the Lender shall not have any
liability or responsibility for any obligation, act or omission of any of its
participants. All rights and powers specifically conferred upon the Lender may
be transferred or delegated to any of the Lender's participants, successors or
assigns.

                  Section 9.9 Execution in Counterparts . This Agreement and
other Loan Documents may be executed in any number of counterparts, each of
which when so executed and delivered shall be deemed to be an original and all
of which counterparts, taken together, shall constitute but one and the same
instrument.

                  Section 9.10 Binding Effect; Assignment; Complete Agreement;
Exchanging Information . The Loan Documents shall be binding upon and inure to
the benefit of the Borrowers and the Lender and their respective successors and
assigns, except that no Borrower shall have the right to assign its rights
thereunder or any interest therein without the Lender's prior written consent.
This Agreement, together with the Loan Documents, comprises the complete and
integrated agreement of the parties on the subject matter hereof and supersedes
all prior agreements, written or oral, on the subject matter hereof. Without
limiting the Lender's right to share information regarding the Borrowers and its
Affiliates with the Lender's participants, accountants, lawyers and other
advisors, the Lender and all direct and indirect subsidiaries of Lender may
exchange any and all information they may have in their possession regarding the
Borrowers and its Affiliates, and the Borrowers waive any right of
confidentiality it may have with respect to such exchange of such information.

                  Section 9.11 Severability of Provisions . Any provision of
this Agreement which is prohibited or unenforceable shall be ineffective to the
extent of such prohibition or unenforceability without invalidating the
remaining provisions hereof.

                  Section 9.12 Headings . Article and Section headings in this
Agreement are included herein for convenience of reference only and shall not
constitute a part of this Agreement for any other purpose.

                  Section 9.13 Governing Law; Jurisdiction, Venue; Waiver of
Jury Trial .

                  (a) The Loan Documents shall be governed by and construed in
accordance with the substantive laws (other than conflict laws) of the State of
Colorado. This Agreement shall be governed by and construed in accordance with
the substantive laws (other than conflict laws) of the State of Colorado.

                                       26
<PAGE>   30

                  (b) Except for "Core Proceedings" under the United States
Bankruptcy Code, Lender and Borrowers agree to submit to binding arbitration all
claims, disputes and controversies between or among them, whether in tort,
contract or otherwise (and their respective employees, officers, directors,
attorneys and other agents) arising out of or relating in any way to the Credit
Facility or the Loan Documents or the negotiation, execution, collateralization,
administration, repayment, modification, extension, substitution, formation,
inducement, enforcement, default or termination thereof. Any arbitration
proceeding will (i) be conducted in Denver, Colorado, (ii) be governed by the
Federal Arbitration Act (Title 9 of the United States Code), and (iii) be
conducted in accordance with the Commercial Arbitration rules of the American
Arbitration Association ("AAA"). The arbitration requirement does not limit the
right of any party to (1) foreclose against any collateral, (2) exercise
self-help remedies relating to any collateral or the proceeds thereof such as
setoff or repossession, or (3) obtain provisional ancillary remedies such as
replevin, injunctive relief, attachment or the appointment of a receiver,
before, during or after the pendency of any arbitration proceeding. This
exclusion does not constitute a waiver of the right or obligation of either
party to submit any dispute to arbitration, including those arising from the
exercise of the actions detailed in clauses (1), (2) or (3) above. Any
arbitration proceeding will be before a single arbitrator selected according to
the Commercial Arbitration Rules of the AAA. The arbitrator will be a neutral
attorney who has practiced in the area of commercial law for a minimum of 10
years. The arbitrator will determine whether or not an issue is arbitratable and
will give effect to the statutes of limitation in determining any claim.
Judgment upon the award rendered by the arbitrator may be entered in any court
having jurisdiction.

                  (c) In any arbitration proceeding the arbitrator will decide
(by documents only or with a hearing at the arbitrator's discretion) any
pre-hearing motions which are similar to motions to dismiss for failure to state
a claim or motions for summary adjudication.

                  (d) In any arbitration proceeding, discovery will be permitted
and will be governed by Colorado Rules of Civil Procedure. All discovery must be
completed no later than 20 days before the hearing date and within 180 days of
the commencement of arbitration proceedings. Any requests for an extension of
the discovery periods, or any discovery disputes, will be subject to final
determination by the arbitrator upon a showing that the request for discovery is
essential for the party's presentation and that no alternative means for
obtaining information is available.

                  (e) The arbitrator shall award costs and expenses of the
arbitration proceeding in accordance with the provisions of the Loan Documents.

                  (f) THE PARTIES WAIVE ANY RIGHT TO TRIAL BY JURY IN ANY ACTION
OR PROCEEDING BASED ON OR PERTAINING TO THIS AGREEMENT.

                  Section 9.14 Joint and Several Liability . (a) Each Borrower
shall be liable for all amounts due to the Lender under this Agreement,
regardless of which Borrower actually receives loans or other extensions of
credit hereunder or the amount of such loans received or the manner in which the
Lender accounts for such loans or other extensions of credit on its books and
records. Each Borrower's Obligations with respect to loans made to it, and each
Borrower's Obligations arising as a result of the joint and several liability of
such Borrower hereunder, with respect to loans made to the other Borrowers
hereunder, shall be separate and distinct obligations, but all such Obligations
shall be primary obligations of such Borrower.

                  (b) Each Borrower's Obligations arising as a result of the
joint and several liability of such Borrower hereunder with respect to loans or
other extensions of credit made to the other Borrowers hereunder shall, to the
fullest extent permitted by law, be unconditional irrespective of (i) the
validity or enforceability, avoidance or subordination of the Obligations of the
other Borrowers or of any promissory note or other document evidencing all or
any part of the Obligations of the other Borrowers, (ii) the absence of any
attempt to collect the Obligations from the other Borrowers, any other
guarantor, or any other security therefor, or the absence of any other action to
enforce the same, (iii) the waiver, consent, extension, forbearance or granting
of any indulgence by the Lender with respect to any provision of any instrument
evidencing the Obligations of the other Borrowers, or any part thereof, or any
other agreement now or hereafter executed by the other Borrowers and delivered
to the Lender, (iv) the failure by the Lender to take any steps to perfect and
maintain its security interest in, or to preserve its rights to, any security or
collateral for the Obligations of the other Borrowers, (v) the Lender's
election, in any proceeding instituted under the

                                       27
<PAGE>   31

Bankruptcy Code, of the application of Section 1111(b)(2) of the Bankruptcy
Code, (vi) any borrowing or grant of a security interest by the other Borrowers,
as debtor-in-possession under Section 364 of the Bankruptcy Code, (vii) the
disallowance of all or any portion of the Lender's claim(s) for the repayment of
the Obligations of the other Borrowers under Section 502 of the Bankruptcy Code,
or (viii) any other circumstances which might constitute a legal or equitable
discharge or defense of a guarantor or of the other Borrowers. With respect to
each Borrower's obligations arising as a result of the joint and several
liability of such Borrower hereunder with respect to loans or other extensions
of credit made to any other Borrower hereunder, each Borrower waives, until the
Obligations shall have been paid in full and this Agreement shall have been
terminated, any right to enforce any right of subrogation or any remedy which
the Lender now has or may hereafter have against the other Borrowers, any
endorser or any guarantor of all or any part of the Obligations, and any benefit
of, and any right to participate in, any security or collateral given to the
Lender to secure payment of the Obligations or any other liability of the other
Borrowers to the Lender.

                  (c) Upon any Event of Default, the Lender may proceed directly
and at once, without notice, against each Borrower to collect and recover the
full amount, or any portion of the Obligations, without first proceeding against
the other Borrowers or any other Person, or against any security or collateral
for the Obligations. Each Borrower consents and agrees that the Lender shall be
under no obligation to marshal any assets in favor of such Borrower or against
or in payment of any or all of the Obligations.

                  Section 9.15. Contribution and Indemnification among the
Borrowers . Each Borrower is obligated to repay the Obligations as joint and
several obligors under this Agreement. To the extent that any Borrower shall,
under this Agreement as a joint and several obligor, repay any of the
Obligations constituting Advances made to another Borrower hereunder or other
Obligations incurred directly and primarily by any other Borrower (an
"Accommodation Payment"), then the Borrower making such Accommodation Payment
shall be entitled to contribution and indemnification from, and be reimbursed
by, each of the other Borrowers in an amount, for each of such other Borrowers,
equal to a fraction of such Accommodation Payment, the numerator of which
fraction is such other Borrower's "Allocable Amount" (as defined below) and the
denominator of which is the sum of the Allocable Amounts of all of the
Borrowers. As of any date of determination, the "Allocable Amount" of each
Borrower shall be equal to the maximum amount of liability for Accommodation
Payments which could be asserted against such Borrower hereunder without (a)
rendering such Borrower "insolvent" within the meaning of Section 101 (31) of
the Bankruptcy Code, Section 2 of the Uniform Fraudulent Transfer Act ("UFTA")
or Section 2 of the Uniform Fraudulent Conveyance Act ("UFCA"), (ii) leaving
such Borrower with unreasonably small capital or assets, within the meaning of
Section 548 of the Bankruptcy Code, Section 4 of the UFTA, or Section 5 of the
UFCA, or (iii) leaving such Borrower unable to pay its debts as they become due
within the meaning of Section 548 of the Bankruptcy Code or Section 4 of the
UFTA, or Section 5 of the UFCA. All rights and claims of contribution,
indemnification and reimbursement under this Section shall be subordinate in
right of payment to the prior payment in full of the Obligations. The provisions
of this Section shall, to the extent expressly inconsistent with any provision
in any Loan Document, supersede such inconsistent provision.

                  Section 9.16 Agency of the Parent for each other Borrower .
Each Borrower (other than the Parent) appoints the Parent as its agent for all
purposes relevant to this Agreement, including the giving and receipt of notices
and execution and delivery of all documents, instruments and certificates
contemplated herein and all modifications hereto. Any acknowledgment, consent,
direction, certification or other action which might otherwise be valid or
effective only if given or taken by all of the Borrowers or acting singly, shall
be valid and effective if given or taken only by the Parent, whether or not any
of the other Borrowers joins therein.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                       28
<PAGE>   32

                  IN WITNESS WHEREOF, the parties hereto have caused this
Agreement to be executed by their respective officers thereunto duly authorized
as of the date first above written.

WELLS FARGO BANK WEST, N.A.

By /s/ Lynn Hout
  -------------------------------
Name: Lynn Hout
     ----------------------------

Its Vice President
    -----------------------------

PENTASTAR COMMUNICATIONS, INC.

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR ACQUISITION CORP. I

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR ACQUISITION CORP. II

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR ACQUISITION CORP. III

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

                                       29
<PAGE>   33

PENTASTAR ACQUISITION CORP. IV

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR ACQUISITION CORP. VI

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR INTERNET, INC.

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR HOLDING CORPORATION

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR TELEMARKETING, INC.

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

PENTASTAR CORPORATION

By /s/ David L. Dunham
  -------------------------------
Name: David L. Dunham
     ----------------------------
Its  Chief Financial Officer
     -----------------------------

                                       30
<PAGE>   34
                       Table of Exhibits and Schedules

            Exhibit A                 Form of Note

            Exhibit B                 Compliance Certificate

                               -------------------

            Schedule 5.1              Trade Names, Chief Executive Office,
                                      Principal Place of Business, and
                                      Locations of Collateral

            Schedule 5.4              Existing Subsidiaries

            Schedule 5.17             Recent Acquisitions

            Schedule 7.1              Permitted Liens

            Schedule 7.2              Permitted Indebtedness and Guaranties

<PAGE>   35

                             Exhibit A to Credit and
                               Security Agreement

         NOTE

                                 [SEE ATTACHED]

<PAGE>   36

                                 PROMISSORY NOTE

$10,000,000.00                                              July 10, 2000

         FOR VALUE RECEIVED EACH OF PENTASTAR COMMUNICATIONS, INC., PENTASTAR
ACQUISITION CORP. I, PENTASTAR ACQUISITION CORP. II, PENTASTAR ACQUISITION CORP.
III, PENTASTAR ACQUISITION CORP. IV, PENTASTAR ACQUISITION CORP. VI, PENTASTAR
INTERNET, INC., PENTASTAR HOLDING CORPORATION, PENTASTAR TELEMARKETING, INC.
(each a Delaware corporation) and PENTASTAR CORPORATION, (a Colorado
corporation) (collectively, the "Maker"), promises to pay to the order of WELLS
FARGO BANK WEST, N.A. (the "Bank"), or its order, on or before July 31, 2001,
the principal sum of TEN MILLION DOLLARS ($10,000,000.00) or so much as may be
advanced and outstanding from time to time (the "Principal Amount") pursuant to
the Credit and Security Agreement of even date herewith between Bank and Maker
(as it may be amended, restated or supplemented from time to time, the "Loan
Agreement") together with interest on the Principal Amount at a rate equal to
the Interest Rate (as defined below).

         This Note is issued to evidence a revolving line of credit from Bank to
Maker made pursuant to the terms of the Loan Agreement, together with all other
amounts due pursuant to the Loan Agreement and the Loan Documents. This Note is
issued pursuant, and is subject, to the Credit Agreement, which provides, among
other things, for acceleration hereof. This Note is the Note referred to in the
Credit Agreement. Bank is entitled to the benefits of certain Security Documents
executed in connection with the Loan Agreement. All capitalized terms used
herein and not defined shall have the meaning given to them in the Loan
Agreement.

         Interest, based upon a three hundred sixty (360) day year and the
actual number of days elapsed, shall accrue daily, and is payable on each
Interest Payment Date (as defined below), and all accrued and unpaid interest
plus the outstanding Principal Amount shall be due on the Termination Date.

         For purposes of this Note, the following terms shall have the meanings
indicated:

         Interest Payment Date. (A) with respect to amounts outstanding
hereunder that bear interest at the LIBOR Based Rate, on the last day of the
relevant Interest Rate Period for all interest accrued through and including
such last day of such Interest Rate Period, and (B) with respect to amounts
outstanding hereunder that bear interest at the Prime Rate, monthly on the last
day of each month for all interest accrued through the last day of such month.

         Interest Rate Period. With respect to amounts outstanding hereunder
that bear interest at the LIBOR Based Rate, a period of one, two or three
months, such period to be determined at the option of Makers in accordance with
the provisions of this Note. The Interest Rate Period selected by Maker must end
prior to the Maturity Date.

         LIBOR Business Day. Any Banking Day on which commercial banks are open
for international business (including dealings in U.S. Dollar deposits) in
London, England.

         LIBOR Based Rate. For any Interest Rate Period, the per annum rate of
interest equal to the sum of (a) the applicable LIBOR Rate in effect on the
first day of such Interest Rate Period, plus (b) two and one-half percent (2
1/2%).

         LIBOR Rate. Shall mean the rate at which U.S. Dollar deposits are
offered by the principal office of designated banks chosen by the British
Banker's Association in London, England to prime banks in the London Interbank
Market at 11:00 A.M. local London time on the first day of each Interest Rate
Period, which rate is displayed on page 3750 of the Telerate Monitor. All
computations of interest shall be calculated on the basis of a 360-day year and
the actual number of days elapsed. Bank's determination of the LIBOR Rate shall
be deemed conclusive absent manifest error.

<PAGE>   37

         (i) Interest Rate. The entire outstanding Principal Amount of the Note
shall accrue interest at the rate provided in clause (A) below, except during
such time periods as the rate provided in clause (B) shall apply.

                  (A) interest shall accrue on the Principal Amount outstanding
under this note from time to time at the prime rate of Bank (which is the
interest rate publicly announced or published from time to time as the prime
rate of Bank and may not be the lowest interest rate charged by Bank) (the
"Prime Rate") in effect on any given day. The Prime Rate applicable hereunder is
adjustable on any date that the Prime Rate changes, regardless of whether Maker
has notice of such change.

                  (B) Maker may, by 11:00 am on any LIBOR Banking Day, request
that Bank convert the interest rate then accruing on any portion of the
Principal Amount to the applicable LIBOR Based Rate in effect on such day, or
that Bank make an Advance at the LIBOR Based Rate as more fully set forth below.
If Maker elects the LIBOR Based Rate as provided herein, the LIBOR Based Rate
will apply to the portion of the Principal Amount designated by Maker for the
Interest Rate Period elected by Maker. Any such election must be made by written
notice to Bank, provided that (i) such notice is irrevocable, (ii) the Interest
Rate Period selected by Maker ends prior to the Maturity Date, (iii) there
exists no Default or Event of Default under the Note or the other Loan Documents
and (iv) Bank has not given Maker any notice of demand, acceleration or other
similar notice in connection with this Note. The Principal Amount shall not be
subject to more than five (5) Interest Rate Periods.

                  On the day following the last day of each Interest Rate
Period, the LIBOR Based Interest Rate applicable to the Principal Amount shall
automatically convert to the Prime Rate unless Maker has (i) given the notice
required above prior to 11:00 a.m. of such day, and (ii) the conditions to
Maker's option to convert the interest rate to the LIBOR Based Rate as set forth
above have been met.

                  Except as specifically provided herein to the contrary, the
portion of the Principal Amount specified in the notice provided pursuant to the
provisions set forth above shall bear interest at the LIBOR Based Rate so
determined from and including the first day of such partial Interest Rate Period
to, but not including, the day immediately following the last day of such
Interest Rate Period.

         (ii) Unavailability of LIBOR Rate. If at any time Bank determines in
good faith that it is not possible to determine the LIBOR Rate, then the Prime
Rate shall be used for determining the Interest Rate.

         (iii) LIBOR Rate Unlawful. If it shall be unlawful or impossible for
Bank to continue maintaining loans bearing interest at the LIBOR Based Rate,
then Bank shall promptly give written notice thereof to Maker (including a
description of the circumstances giving rise to such determination), whereupon
Bank's obligation to permit the Principal Amount to accrue interest at the LIBOR
Based Rate under the Note shall be suspended and interest payable hereunder
shall be payable at the Prime Rate, unless Bank may lawfully continue to
maintain the Principal Amount at the LIBOR Based Rate until the end of the then
current Interest Rate Period, at which time the interest rate shall revert to
the Prime Rate. If at any time subsequent to the giving of such notice the Bank
determines that, because of a change in circumstances, the LIBOR Based Rate is
again available to Maker hereunder, Bank will so advise Maker, and the Principal
Amount shall, if Maker so elects, again accrue interest at the LIBOR Based Rate
(if applicable pursuant to subsection (i) above) on the first day of the
applicable Interest Rate Period.

         (iv) Prepayment:

              (A) All or any portion of the Principal Amount accruing interest
at the Prime Rate may be prepaid without penalty at any time.

              (B) All or any portion of the Principal Balance accruing interest
at the LIBOR Based Rate may be prepaid at any time, subject to payment of a
prepayment premium if the date of prepayment is a date other than the end of an
Interest Rate Period, as described in the following paragraph.

                  Maker shall give at least ten (10) Banking Days' prior written
irrevocable notice to Bank specifying the amount to be prepaid and the intended
date of prepayment, which date of prepayment must not be more than forty-five
(45) days after the date of such notice. The portion of the Principal Balance
specified in any such irrevocable notice of prepayment shall, notwithstanding
anything to the contrary contained in this Note, be

                                       2
<PAGE>   38

absolutely and unconditionally due and payable on the date specified in such
notice. No prepayment premium is payable if prepayment occurs on the last day of
an Interest Rate Period. If prepayment does not occur on the last day of an
Interest Rate Period, Maker shall pay to Bank, contemporaneously with such
prepayment, a prepayment premium equal to the amount of any and all losses,
costs and expenses, as well as any loss of anticipated, expected or projected
revenues and profits, incurred or suffered by the Bank as a result of such
prepayment being made prior to the end of an Interest Rate Period. Bank shall
deliver to Maker a statement setting forth the amount and basis of determination
of the prepayment premium, if any, due in connection with a prepayment of the
Principal Balance in accordance with the provisions of this paragraph. Bank
shall make such calculation based upon its reasonable judgment, which
calculation shall be binding absent manifest error. No prepayment premium
payable under this paragraph shall in any event or under any circumstances be
deemed or construed to be a penalty. Any payment of the Principal Amount after
Bank has declared the Principal Amount immediately due and payable in accordance
with the terms of this Note or the Loan Documents shall be deemed to be a
voluntary prepayment for all purposes of this paragraph, and a prepayment
premium calculated pursuant to the provisions of this paragraph shall be payable
with respect to the portion thereof bearing interest at the applicable LIBOR
Based Rate immediately prior to such declaration. Maker and Bank agree that Bank
shall not be obligated or required to have actually reinvested the prepaid
portion of the Principal Balance in any U.S. Government Treasury Obligations or
any other investment as a condition precedent to Maker being obligated to pay a
prepayment premium calculated in accordance with the provisions of this
paragraph. Maker shall, upon receipt of such statement and contemporaneously
with any such prepayment of the Principal Balance, remit to Bank the prepayment
premium, if any, due in connection therewith, as calculated pursuant to the
provisions of this paragraph. Bank shall not be obligated to accept any
prepayment of the Principal Balance unless it is accompanied by the prepayment
premium, if any, due in connection therewith as calculated pursuant to the
provisions of this paragraph.

              (C) All sums that become due and payable by Maker in accordance
with the above provisions shall be and shall under all circumstances be deemed
to constitute additional interest on, and shall be evidenced by, this Note.

              (D) All payments hereunder shall be applied in the manner set
forth in the Loan Agreement.

         At the Bank's discretion overdue principal and (to the extent permitted
under applicable law) interest not paid within ten days after notice to the
Maker that the same is due, whether caused by acceleration of maturity or
otherwise, shall bear interest until paid at a fluctuating annual rate equal to
three (3) percentage points above the Prime Rate.

         It is not intended hereby to charge interest at a rate in excess of the
maximum rate of interest permitted to be charged to the Maker under applicable
law, but if, notwithstanding, interest in excess of such maximum rate shall be
paid hereunder, the excess shall be retained by the holder of this Note as
additional cash collateral for the payment of the Loan, unless such retention is
not permitted by law, in which case the interest rate on this Note shall be
adjusted to the maximum permitted under applicable law during the period or
periods that the interest rate otherwise provided herein would exceed such rate.

         All payments of this Note shall be made in lawful money of the United
States of America at the Bank's offices at MAC # C7301-031, 1740 Broadway,
Denver, Colorado 80274, or at such other place as the Bank may designate to the
Maker in writing.

         Time is of the essence hereof. In the event of (i) any default in the
payment of principal or interest when due and payable under the terms of this
Note, (ii) any Event of Default under the Loan Agreement, or (iii) any default
under any other Loan Document, then the whole principal sum plus accrued
interest and all other obligations of the Maker to holder, direct or indirect,
absolute or contingent, now existing or hereafter arising, shall, at the option
of the holder of this Note, become immediately due and payable without notice or
demand, and the holder of this Note shall have and may exercise any or all of
the rights and remedies provided herein and in the Loan Agreement, and the other
Loan Documents, as they may be amended, modified or supplemented from time to
time.

         If the Maker fails to pay any amount due under this Note and the Bank
has to take any action to collect the amount due or to exercise its rights under
the Loan Agreement or the Loan Documents, including without limitation,
retaining attorneys for collection of this Note, or if any suit or proceeding is
brought for the recovery of all or any

                                       3
<PAGE>   39

part of or for protection of the indebtedness or to foreclose the Loan Documents
or to enforce the Bank's rights under the Loan Agreement, or the Loan Documents,
then the Maker agrees to pay on demand all costs and expenses of any such action
to collect, suit or proceeding, and any appeal of any such action, suit or
proceeding, incurred by the Bank, including but not limited to the reasonable
fees and disbursements of the Bank's attorneys and their staff.

         The Maker and any endorser hereof waive presentment for payment,
protest, notice of dishonor and protest, and consent to any extension of time
with respect to any payment due under this Note, to any substitution or release
of collateral pursuant to the Loan Agreement, and to the addition or release of
any party. No waiver of any payment under this Note shall operate as a waiver of
any other payment.

         If any provision in this Note shall be held invalid, illegal or
unenforceable in any jurisdiction, the validity, legality or enforceability of
any defective provision shall not be in any way affected or impaired in any
other jurisdiction.

         No delay or failure of the holder of this Note in the exercise of any
right or remedy provided for hereunder shall be deemed a waiver of such right by
the holder hereof, and no exercise of any right or remedy shall be deemed a
waiver of any other right or remedy which the holder may have.

         All notices given hereunder shall be given in accordance with the
notice provisions of the Loan Agreement.

         At the option of the holder hereof, an action may be brought to enforce
this Note in the manner set forth in the Loan Agreement.

         This Note is to be governed by and construed according to the laws of
the State of Colorado.

                                       4
<PAGE>   40

DATED as of the day and year first set forth above.

MAKER:

PENTASTAR COMMUNICATIONS, INC.

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR ACQUISITION CORP. I

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR ACQUISITION CORP. II

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR ACQUISITION CORP. III

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR ACQUISITION CORP. IV

By
   ----------------------------------
Name:
     --------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

                                       5
<PAGE>   41

PENTASTAR ACQUISITION CORP. VI

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR INTERNET, INC.

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR HOLDING CORPORATION

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR TELEMARKETING, INC.

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

PENTASTAR CORPORATION

By
   ----------------------------------
Name:
     --------------------------------
Its
   ----------------------------------

<PAGE>   42

                                     RECEIPT

         I hereby state that on _________, 2000, I received the original
Promissory Note, dated __________, 2000, payable to the order of Wells Fargo
Bank West, N. A. in the principal amount of $10,000,000 from Pentastar
Communications, Inc., Pentastar Acquisition Corp. I, Pentastar Acquisition Corp.
II, Pentastar Acquisition Corp. III, Pentastar Acquisition Corp. IV, Pentastar
Acquisition Corp. VI, Pentastar Internet, Inc., Pentastar Holding Corporation,
Pentastar Telemarketing, Inc. and Pentastar Corporation.

                                         WELLS FARGO BANK WEST, N. A.

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

<PAGE>   43

                  Exhibit B to Credit and Security Agreement

                             COMPLIANCE CERTIFICATE

                                 [SEE ATTACHED]

<PAGE>   44

                   Exhibit B to Credit and Security Agreement

                             COMPLIANCE CERTIFICATE

To:         Lynn N. Hout, Wells Fargo Bank West, N.A.

Date:       ______________________________________
Subject:    PentaStar Financial Statements

            In accordance with our Credit and Security Agreement dated as of
July 10, 2000 (the "Credit Agreement"), attached are the financial statements
(the "Current Financials") of Pentastar Communications, Inc. (the "Parent") as
of and for the [quarter]/[fiscal year] ended ______________, ___ (the "Reporting
Date"). All terms used in this certificate have the meanings given in the Credit
Agreement.

            The undersigned hereby certifies that the Current Financials have
been prepared in accordance with GAAP, subject to year-end audit adjustments,
and fairly present Parent's financial condition and the results of its
operations as of the date thereof.

            Events of Default. (Check one):

         o  The undersigned has no knowledge of the occurrence of a Default or
            Event of Default under the Credit Agreement.

         o  The undersigned has knowledge of the occurrence of a Default or
            Event of Default under the Credit Agreement and attached hereto is a
            statement of the facts with respect to thereto.

            Financial Covenants. The undersigned hereby certifies as follows:

         1. Minimum Current Ratio. Pursuant to Section 6.11 of the Credit
Agreement, as of the Reporting Date, the Parent's consolidated Current Ratio was
_____ to 1.00 which [ ] satisfies [ ] does not satisfy the requirement that such
ratio be no less than 1.5 to 1.00 on the Reporting Date. For purposes hereof:

            a. Parent's consolidated current assets equals $____________; and

            b. Parent's consolidated current liabilities (excluding the
            outstanding principal balance of the Note and the Merrill Lynch Long
            Term Debt) equals $__________.

<PAGE>   45

         2. Total Leverage Ratio. Pursuant to Section 6.12 of the Credit
Agreement, as of the Reporting Date, the Total Leverage Ratio was _____ to 1.00
which [ ] satisfies [ ] does not satisfy the requirement that such ratio not
exceed 1.5 to 1.00 on the Reporting Date. For purposes hereof(1):

            1. Parent's total consolidated Funded Debt equals: $__________;

            2. Parent's consolidated EBITDA equals $__________, consisting of
            (i) pretax earnings from continuing operations ($__________), (ii)
            Interest Expense ($__________) and (iii) depreciation, depletion,
            and amortization of tangible and intangible assets ($__________),
            before (a) special extraordinary gains ($__________) and losses
            ($__________) and (b) minority interests ($__________), plus
            corporate overhead annualized based on the level incurred in the
            most recent quarter ($__________).

            3. For each Borrower, the calculations set forth in the following
            table are true:

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
                                                                         SPECIAL        SPECIAL        MINORITY       ANNUALIZED
                                   PRETAX      INTEREST   DEPRECIATION   EXTRA-ORDINARY EXTRA-ORDINARY INTERESTS*     CORP
BORROWER               EBITDA*     EARNINGS*   EXPENSE*   ETC.*          GAINS*         GAINS*                        OVERHEAD*
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
<S>                    <C>         <C>         <C>        <C>            <C>            <C>            <C>            <C>
Pentastar              $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Communications, Inc.
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar              $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Acquisition Corp. I
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar              $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Acquisition Corp. II
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar              $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Acquisition Corp. III
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar              $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Acquisition Corp. IV
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
 Pentastar             $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Acquisition Corp. VI
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar Internet,    $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Inc.
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar Holding      $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Corporation
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar              $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
Telemarketing, Inc.
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
Pentastar Corporation  $_____      $_____      $_____     $_____         $_____         $____          $_____         $_____
---------------------- ----------- ----------- ---------- -------------- -------------- -------------- -------------- -------------
</TABLE>

* FOR THE MOST RECENTLY COMPLETED FOUR FISCAL QUARTERS.

                  Attached hereto are all relevant facts in reasonable detail to
evidence, and the computations of the financial covenants referred to above.
These and all other computations made in connection herewith were made in
accordance with GAAP.

----------------
(1) For purposes of all calculations below, EBITDA shall be calculated as if all
assets acquired (including without limitation acquisitions of stock) on any date
during the period of determination were acquired on the first day in such period
of determination, and all assets sold (including without limitation dispositions
of stock) on any date during the period of determination were sold on the first
day in such period of determination, in each case with costs adjusted to the
levels that any Borrower will incur.

<PAGE>   46

PENTASTAR COMMUNICATIONS, INC.

By
  ---------------------------------
     Its Chief Financial Officer

<PAGE>   47

                 Schedule 5.1 to Credit and Security Agreement

                                 [SEE ATTACHED]

<PAGE>   48

                                   EXHIBIT 5.1

<TABLE>
<CAPTION>
                                    PRINCIPAL PLACE
BORROWER                            OF BUSINESS               OTHER LOCATIONS      OTHER BUSINESS NAMES
<S>                                 <C>                       <C>                  <C>
PentaStar Communications, Inc.      4640 E. Elwood St.        1522 Blake Street    Optimal Communications, Inc.
EIN 84-1502003                      Suite #16                 Denver, CO 80202     ParTel, Inc
Jurisdiction of Incorp:  DE         Phoenix, AZ 85040
                                    (ParTel Division)

PentaStar Internet, Inc.            1522 Blake Street         N/A                  N/A
EIN 84-1518608                      Denver, CO 80202
Jurisdiction of Incorp:  DE

PentaStar Corporation               1743 W. Quincy Ave.       8455 Highway 261     Telecomm Industries Corp.
EIN 84-1542925                      Suite 143                 Newburgh, IN 47630
Jurisdiction of Incorp:  CO         Naperville, IL 60540
                                                              806 Cedar Parkway
                                                              Schererville, IN 46375

                                                              401 Colfax Avenue
                                                              Suite 308
                                                              South Bend, IN 46617

                                                              2508 N. Richmond St.
                                                              Appleton, WI 54911

                                                              311 West Superior
                                                              Suite 402
                                                              Chicago, IL 60610

                                                              6631 Commerce Pkwy.
                                                              Suite L
                                                              Dublin, OH 43017
                                                              (Franklin County)

                                                              741 Congress Park Drive
                                                              Dayton, OH 45459
                                                              (Montgomery County)

                                                              941 Ashwaubenon Street
                                                              Suite D
                                                              Green Bay, WI 54307

                                                              1200 Resource Drive
                                                              Brooklyn Heights, OH 44131
                                                              (Cuyahoga County)

                                                              8450 Westfield Blvd.
                                                              Suite 100
                                                              Indianapolis, IN 46240

                                                              11838 Capital Way
                                                              Louisville, KY 40299

                                                              9310 Progress Parkway
                                                              Mentor, OH 44060
                                                              (Lake County)
</TABLE>

<PAGE>   49

<TABLE>
<CAPTION>
                                    PRINCIPAL PLACE
BORROWER                            OF BUSINESS                  OTHER LOCATIONS          OTHER BUSINESS NAMES
<S>                                 <C>                          <C>                      <C>
PentaStar Acquisition Corp. I       7076 S. Alton Way            6th South Tejon          DMA Ventures, Inc. dba Access
EIN 84-1518609                      Bldg. A                      Suite 680                Communications
Jurisdiction of Incorp:  DE         Englewood, CO 80112          Colorado Springs,OC      Mergerco 1, Inc.
                                                                 CO 80903

PentaStar Acquisition Corp. II      4122 128th Ave. SE           12300 S E Mallard Way    ICM Communications
EIN 84-1518610                      Suite 300                    Suite 250                Integration, Inc.
Jurisdiction of Incorp:  DE         Bellevue, WA 98006           Milwaukie, OR 97222      OC Mergerco 2, Inc.

PentaStar Acquisition Corp. III     4122 128th Ave. SE           N/A                      Network Communications, Inc.
EIN 84-1525015                      Suite 300                                             OC Mergerco 3, Inc.
Jurisdiction of Incorp:  DE         Bellevue, WA 98006

PentaStar Acquisition Corp. IV      745 Atlantic Ave.            300 Metrocenter Blvd.    US TeleCenters, Inc.
EIN 84-1534698                      Boston, MA 02111             Warwick, RI 02886        Vermont Network Services Corp.
Jurisdiction of Incorp:  DE                                                               VSI Network Solutions, Inc.
                                                                 233 Stevens Street       Eastern Telecom, Inc.
                                                                 Hyannis, MA 02601        OC Mergerco 4, Inc.
                                                                 (Barnstable County)

                                                                 60 K Street South
                                                                 Boston, MA 02127
                                                                 (Suffolk County)

                                                                 803 Summer St.
                                                                 South Boston, MA 02110
                                                                 (Suffolk County)

                                                                 270 Bridge Street
                                                                 Suite 304
                                                                 Dedham, MA 02026
                                                                 (Norfolk County)

                                                                 230 Washington Avenue
                                                                 Extension
                                                                 Albany, NY 12203
                                                                 (Albany County)

                                                                 22 Scaled Avenue
                                                                 Rutland, VT 05701

                                                                 13 Kilburn Street
                                                                 Burlington, VT 05401

                                                                 142 Boynton Avenue
                                                                 Plattsburgh, NY 12901
                                                                 (Clinton County)

PentaStar Acquisition Corp. VI      7950 Dublin Blvd.,            N/A                     Resource Communications, Inc.
EIN 84-1539525                      Suite 101
Jurisdiction of Incorp:  DE         Dublin, CA 94568

PentaStar Telemarketing, Inc.       745 Atlantic Ave.             233 Stevens Street      US TeleCenters, Inc.
EIN 84-1534696                      Boston, MA 02111              Hyannis, MA 02601
Jurisdiction of Incorp:  DE

PentaStar Holding Corp.             1522 Blake Street             N/A                     N/A
EIN 84-1524727                      Denver, CO 80202
Jurisdiction of Incorp:  DE
</TABLE>

                                       10
<PAGE>   50

                  Schedule 5.4 to Credit and Security Agreement

                                 [SEE ATTACHED]

<PAGE>   51

                                   Exhibit 5.4

                                  Subsidiaries

PentaStar Communications, Inc.
     o   PentaStar Acquisition Corp. I
     o   PentaStar Acquisition Corp. II
     o   PentaStar Acquisition Corp. III
     o   PentaStar Acquisition Corp. IV
     o   PentaStar Acquisition Corp. VI
     o   PentaStar Internet, Inc.
     o   PentaStar Holding Corporation
     o   PentaStar Telemarketing, Inc.
     o   PentaStar Corporation

PentaStar Acquisition Corp. I - None

PentaStar Acquisition Corp. II - None

PentaStar Acquisition Corp. III - None

PentaStar Acquisition Corp. IV - None

PentaStar Acquisition Corp. VI - None

PentaStar Internet, Inc. - None

PentaStar Holding Corporation - None

PentaStar Telemarketing Inc. - None

PentaStar Corporation - None

<PAGE>   52

                 Schedule 5.17 to Credit and Security Agreement

                               Recent Acquisitions

                                 [SEE ATTACHED]

<PAGE>   53

                                  Exhibit 5.17

                                  Acquisitions

1. DMA Ventures, Inc., dba Access Communications
     a. Acquired by PentaStar Acquisition Corp. I, fka OC Mergerco 1, Inc.
     b. Acquired by merger. Closed on October 26, 1999.

2. ICM Communications Integration, Inc.
     a. Acquired by PentaStar Acquisition Corp. II, fka OC Mergerco 2, Inc.
     b. Acquired by merger. Closed on October 26, 1999.

3. NCI Communications, Inc.
     a. Acquired by PentaStar Acquisition Corp. III, fka OC Mergerco 3, Inc.
     b. Acquired by asset purchase. Closed on February 22, 2000.

4. USTeleCenters, Inc. and Vermont Network Services Corporation
     a. Acquired by PentaStar Acquisition Corp. IV, fka OC Mergerco 4, Inc.
     b. Acquired by asset purchase. Closed on February 18, 2000.

5. ParTel, Inc.
     a. Acquired by PentaStar Communications, Inc.
     b. Acquired by merger. Closed on March 17, 2000.

6. Resource Communications, Inc.
     a. Acquired by PentaStar Acquisition Corp. VI
     b. Acquired by merger. Closed on March 31, 2000.

7. VSI Network Solutions, Inc. dba Eastern Telecom, Inc.
     a. Acquired by PentaStar Acquisition Corp. IV, fka OC Mergerco 4, Inc.
     b. Acquired by asset purchase. Closed on May 18, 2000.

8. Telecomm Industries, Inc. (closing to be completed)
     a. Acquired by PentaStar Corporation.
     b. Acquired by asset purchase.

<PAGE>   54

                  Schedule 7.1 to Credit and Security Agreement

                                 [SEE ATTACHED]

<PAGE>   55

                                   Exhibit 7.1

                           Existing Security Interests

1. BancBoston Leasing, Inc. as secured party under lease agreement with US
   TeleCenters, Inc. nka PentaStar Acquisition Corp. IV for office equipment as
   scheduled on Exhibit 7.2.

2. Rockford Industries, Inc. as secured party under lease agreement with US
   TeleCenters, Inc. nka PentaStar Acquisition Corp. IV for office equipment as
   scheduled on Exhibit 7.2.

3. Newcourt Communications Finance Corporation as secured party under lease
   agreement with US TeleCenters, Inc. nka PentaStar Acquisition Corp. IV for
   computer equipment as scheduled on Exhibit 7.2.

4. Imperial Business Credit, Inc. (assignee of lessor) as secured party under
   lease agreement with ParTel, Inc. nka PentaStar Communications, Inc. for
   computer equipment as scheduled on Exhibit 7.2.

<PAGE>   56

                  Schedule 7.2 to Credit and Security Agreement

                                 [SEE ATTACHED]

<PAGE>   57

                                   Exhibit 7.2

                                  Indebtedness

<TABLE>
<S>                                                              <C>
1. Capital Lease Agreement with BancBoston Leasing, Inc.         $32,168

2. Capital Lease Agreement with Rockford Industries, Inc.        $75,497

3. Capital Lease Agreement with Newcourt Communications          $31,159
         Finance Corporation

4. Capital Lease Agreement with Alliance Capital Funding         $10,604
         Corporation
</TABLE>

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