<PAGE>   1

                                                                   Exhibit 10.2



                      FOURTH AMENDMENT TO CREDIT AGREEMENT

         THIS FOURTH AMENDMENT (this "AMENDMENT") is entered into as of October
31, 2000, to be effective as of the Effective Date (hereinafter defined) among
INTERMEDIA COMMUNICATIONS INC. ("BORROWER"), Lenders under the Credit Agreement
(defined below), BANK OF AMERICA, N.A., in its capacity as Administrative Agent
for Lenders under the Credit Agreement ("ADMINISTRATIVE AGENT"), and Guarantors
under the Credit Agreement. Reference is made to the Revolving Credit Agreement,
dated as of December 22, 1999 (as amended to date, the "CREDIT AGREEMENT"),
among Borrower, Administrative Agent, and Lenders party thereto.

                                    RECITALS

         A.       Borrower has requested that Lenders amend the Credit Agreement
and Loan Documents to increase the aggregate Committed Sum (as defined in the
Credit Agreement) from $100,000,000 to $350,000,000 and to increase the
Telecommunications Commitment from $25,000,000 to $275,000,000.

         B.       Borrower and Toronto Dominion (Texas), Inc. ("TD") have
requested that lenders amend the Credit Agreement and Loan Documents to remove
TD as a Lender and as Documentation Agent, and to substitute Bank of America,
N.A. as the new Documentation Agent.

         C.       Borrower has requested that Lenders agree to amend certain
additional provisions of the Credit Agreement.

         D.       As an inducement to Lenders to agree to such amendments,
Borrower proposes to have WorldCom, Inc. ("WORLDCOM") execute and deliver a
Guaranty pursuant to which WorldCom guarantees the Obligation (as defined in the
Credit Agreement).

         E.       In consideration of the Guaranty by WorldCom and subject to
the terms and conditions of this Amendment, Lenders are willing to agree to such
amendments.

Accordingly, for valuable and acknowledged consideration, Borrower, Lenders, and
Guarantors agree as follows:

PARAGRAPH 1       TERMS AND REFERENCES. Unless otherwise stated in this
amendment (a) terms defined in the Credit Agreement have the same meanings when
used in this amendment, (b) references to "SECTIONS," "SCHEDULES," and
"EXHIBITS" are to the Credit Agreement's sections, schedules, and exhibits, and
(c) references to "PARAGRAPHS" are to paragraphs in this Amendment.

PARAGRAPH 2       AMENDMENTS.

         2.1      DEFINITIONS.

         (a)      The definition of "Applicable Margin" is deleted in its
entirety and the following is substituted therefor:

         "APPLICABLE MARGIN means either:

                  (a)      on any date of determination occurring prior to the
         Fourth Amendment Date, 1.75% for Base Rate Borrowings and 2.750% for
         Eurodollar Rate Borrowings; or




                                            FOURTH AMENDMENT TO CREDIT AGREEMENT
<PAGE>   2

                   (b)     on any date of determination occurring on and after
         the Fourth Amendment Date, 0.00% for Base Rate Borrowings and, for
         Eurodollar Rate Borrowings, the percentage set forth in the table below
         which corresponds to the lowest rating (or implied rating) established
         by either S&P and Moody's (as defined in the definition of "Cash
         Equivalents" below) applicable to WorldCom's senior, unsecured,
         non-credit-enhanced, long term indebtedness for borrowed money (the
         "DEBT RATING"):

                         DEBT RATING             APPLICABLE MARGIN FOR
                                                   EURODOLLAR RATE
                                                      BORROWINGS
                   -----------------------       ---------------------
                          CATEGORY 1                    .550%
                    A- or higher by S&P
                   A3 or higher by Moody's

                          CATEGORY 2                    .750%
                     Less than A- by S&P
                  Less than A3 by Moody's

         For purposes of determining the Applicable Margin for Eurodollar Rate
         Borrowings, (i) if neither Moody's nor S&P shall have in effect a Debt
         Rating (other than by reason of the circumstances referred to in the
         last sentence of this definition), then both such rating agencies will
         be deemed to have established a Debt Rating in Category 2; (ii) if only
         one of Moody's or S&P shall have in effect a Debt Rating, Borrower and
         Lenders will negotiate in good faith to agree upon another rating
         agency to be substituted for the rating agency which shall not have a
         rating in effect, and in the absence of such agreement the Applicable
         Margin will be determined by reference to the available rating; (iii)
         if the ratings established by Moody's and S&P shall differ and either
         Debt Rating shall be lower than the ratings set forth in Category 1,
         the Applicable Margin shall be determined by reference to Category 2;
         and (iv) if any Debt Rating established by Moody's or S&P shall be
         changed (other than as a result of a change in the rating system of
         either Moody's or S&P), such change shall be effective as of the date
         on which such change is first announced by the rating agency making
         such change. If the rating system of either Moody's or S&P shall change
         prior to the payment in full of the Obligation and the cancellation of
         all commitments to lend hereunder, Borrower and Lenders shall negotiate
         in good faith to amend the references to specific ratings in this
         definition to reflect such changed rating system. If both Moody's and
         S&P shall cease to be in the business of rating corporate debt
         obligations, Borrower and Lenders shall negotiate in good faith to
         agree upon a substitute rating agency and to amend the references to
         specific ratings in this definition to reflect the ratings used by such
         substitute rating agency."

         (b)      The definition of "Guaranty" is deleted in its entirety and
the following is substituted therefor:

         "GUARANTY means, individually, each of the following, and GUARANTIES
         means collectively: (a) a Guaranty in substantially the form and upon
         the terms of EXHIBIT C, executed and delivered by any Person pursuant
         to the requirements of the Loan Documents, as amended, modified,
         supplemented, restated, ratified, or reaffirmed in accordance with the
         Loan Documents, and (b) any Digex Limited Guaranty."




                                       2    FOURTH AMENDMENT TO CREDIT AGREEMENT
<PAGE>   3

         (c)      The definition of "Required Lenders" is deleted in its
entirety and the following is substituted therefor:

         "REQUIRED LENDERS means (a) on any date of determination prior to the
         Termination Date, those Lenders holding 100% of the Total Commitment,
         or (b) on any date of determination occurring after the Termination
         Date, those Lenders holding 100% of the outstanding Principal Debt."

         (d)      The definition "Telecommunications Commitment" is deleted in
its entirety and the following is substituted therefor:

         "TELECOMMUNICATIONS COMMITMENT means an amount equal to $275,000,000."

         (e)      The definition of "Termination Date" is deleted in its
entirety and the following is substituted therefor:

         "TERMINATION DATE means the earlier of (a) June 30, 2001, (b) the
         consummation of the Merger, (c) the date upon which any Merger
         Termination Event shall have occurred, and (d) with respect to any
         Facility, the effective date of any other termination or cancellation
         of Lenders' commitments to lend under such Facility, in accordance with
         this Agreement."

         (f)      The following definitions of "Digex," "Digex Limited
Guaranty," "Documentation Agent," "Fourth Amendment," "Fourth Amendment Date,"
"Maximum Digex Liability," "Merger," "Merger Agreement," "Merger Termination
Event," "WorldCom," and "WorldCom Subordinated Debt" shall be alphabetically
inserted in Section 1.1 to read as follows:

         "DIGEX" means Digex, Incorporated, a Delaware corporation.

         "DIGEX LIMITED GUARANTY means a limited Guaranty in substantially the
         form and upon the terms of EXHIBIT C-2 executed and delivered by Digex
         or any of its Subsidiaries pursuant to the requirement of the Loan
         Documents, as amended, modified, supplemented, restated, ratified, or
         reaffirmed in accordance with the Loan Documents."

         "DOCUMENTATION AGENT means Bank of America, N.A., and its respective
         permitted successors or assigns as "Documentation Agent" under this
         Agreement."

         "FOURTH AMENDMENT means that certain Fourth Amendment to Credit
         Agreement dated as of October 31, 2000, among Borrower, Administrative
         Agent, and Lenders."

         "FOURTH AMENDMENT DATE means the date upon which the Fourth Amendment
         becomes effective in accordance with the terms of such Fourth
         Amendment."

         "MAXIMUM DIGEX LIABILITY" means the greater of either (a) $90,000,000
         or (b) the aggregate amount of any loan, advance, extension of credit,
         or capital contribution from any Company to Digex or any of its
         Subsidiaries made onor after the Fourth Amendment Date or any
         investment in Digex or any of its Subsidiaries by any Company made on
         or after the Fourth Amendment Date less (x) any repayment of any such
         loan, advance, extension of credit, or investment by Digex or any of
         its Subsidiaries and (y) the amount of all dividends and distributions
         received by any Company from Digex or any of its Subsidiaries.

         "MERGER means the merger consummated pursuant to the Merger Agreement."




                                       3    FOURTH AMENDMENT TO CREDIT AGREEMENT
<PAGE>   4

         "MERGER AGREEMENT means the Agreement and Plan of Merger among
         WorldCom,Inc, Wildcat Acquisition Corp., and Borrower dated September
         1, 2000, together with all amendments or modifications thereto effected
         in accordance with SECTION 9.30.

         "MERGER TERMINATION EVENT means the occurrence of one or more of the
         following events: (a) any termination by any party thereto of the
         Merger Agreement in accordance with the terms of the Merger Agreement,
         whether or not such termination is within such party's control, or (b)
         any public announcement made or press release issued by any party to
         the Merger Agreement stating that it does not intend to pursue
         consummation of the Merger, or seek shareholder approval, or any public
         statement having a similar effect."

         "WORLDCOM means WorldCom, Inc., a Georgia corporation."

         "WORLDCOM SUBORDINATED DEBT means any Debt arising under that certain
         Note Purchase Agreement dated as of October 31, 2000, with respect to
         the 14.12% Senior Notes of Borrower due October 31, 2009."

         2.2      FEES. SECTION 5.3 is deleted in its entirety and the following
is substituted therefor:

                  "5.3     REVOLVER FACILITY COMMITMENT FEES. Following the
         Closing Date, Borrower shall pay to Administrative Agent, for the
         ratable account of Lenders, a commitment fee, payable in installments
         in arrears, on each March 31, June 30, September 30, and December 31
         and on the Termination Date of each Facility; commencing March 31,
         2000. Each installment shall be in an amount equal to the amount by
         which (a) the sum of the average daily Total Commitment exceeds (b) the
         average daily Principal Debt, in each case during the period from and
         including the last payment date to and excluding the payment date for
         such installment multiplied by a percentage equal to (i) for the period
         from the Closing Date up to the Fourth Amendment Date, (x) 1.250%, if
         the sum of the average daily Principal Debt for such period is less
         than or equal to 33.0% of the average daily Total Commitment for such
         period; (y) 1.00%, if the average daily Principal Debt during such
         period is greater than 33.0% of the average daily Total Commitment
         during said period, but less than or equal to 67.0% of the average
         daily Total Commitment during such period; and (z) .750%, if the
         average daily Principal Debt during such period is greater than 67.0%
         of the average daily Total Commitment during such period, or (ii) for
         the period on and after the Fourth Amendment Date, .100%; provided
         that, each such installment of commitment fees shall be calculated in
         accordance with Section 5.1(f). Solely for the purposes of this Section
         5.3, "ratable" shall mean, for any period of determination, with
         respect to any Lender, that proportion which (x) the sum of the average
         daily unused Committed Sums of such Lender under all Facilities during
         such period bears to (y) the average daily unused Total Commitment
         during such period."

         2.3      SECURITY AGREEMENTS. SECTION 6.1(c) is amended by adding the
following at the end of such Section:

         "Notwithstanding the foregoing or anything else to the contrary
         contained in any Loan Document, the liability of Digex and its
         Subsidiaries under the Loan Documents shall be limited in the aggregate
         to the Maximum Digex Liability."

         2.4      GUARANTIES. SECTION 6.2 is amended by adding the following
sentence at the end of such Section:




                                       4    FOURTH AMENDMENT TO CREDIT AGREEMENT

<PAGE>   5

         "Concurrently with the Fourth Amendment Date, as an inducement for
         Agents and Lenders to enter into the Fourth Amendment, Borrower shall
         cause WorldCom to execute and deliver to Administrative Agent a
         Guaranty."

         2.5      DIGEX GUARANTY. A new Section 6.7 is added as follows:

                  "6.7     Digex Guaranty. As an inducement to Agents and
         Lenders to enter into this Agreement, Digex shall execute and deliver
         to Administrative Agent the Digex Limited Guaranty (substantially in
         the form and upon the terms of EXHIBIT C-2), guaranteeing the Maximum
         Digex Liability."

         2.6      CONDITIONS PRECEDENT TO EACH BORROWING. SECTION 7.3, CLAUSES
(a) and (c) are deleted in their entirety and the following are substituted
therefor:

         "(a) Administrative Agent shall have timely received therefor a Notice
         of Borrowing executed by Borrower and consented to by WorldCom;"

         "(c) no change in the financial condition, business operations, or
         prospects since June 30, 2000, of any Company which could reasonably be
         expected to be a Material Adverse Event shall have occurred;"

         2.7      REPRESENTATIONS AND WARRANTIES. The preamble to SECTION 8 is
deleted in its entirety and the following is substituted therefor:

         "Borrower and each Guarantor (other than WorldCom) represent and
         warrant to Administrative Agent and Lender, as follows:"

         2.9      COVENANTS. The preamble to SECTION 9 is amended by inserting
the phrase "(other than WorldCom)" after the word "Guarantor" in the first line
thereof.

         2.10     DEBT AND GUARANTIES. A new SECTION 9.12(p) is added as
follows:

         "(p) To the extent permitted by the Existing Senior Notes and the
         Existing Subordinated Notes, the WorldCom Subordinated Debt."

         2.11     MERGERS AND DISSOLUTIONS. SECTION 9.18 is deleted in its
entirety and the following is substituted therefor:

                  "9.18    MERGERS AND DISSOLUTIONS; SALE OF CAPITAL STOCK. No
         Company will, directly or indirectly, merge or consolidate with any
         other Person, other than (a) as a result of the Merger or a Permitted
         Acquisition, (b) mergers or consolidations involving Borrower if
         Borrower is the surviving entity, (c) mergers among Wholly-owned
         Companies; provided that, in any merger involving Borrower (including a
         Permitted Acquisition effected as a merger), Borrower must be the
         surviving entity, and, in any merger involving any other Company
         (including a Permitted Acquisition effected as a merger), a Company
         must be the surviving entity; provided further that, from and after the
         Fourth Amendment Date, no merger or consolidation (other than the
         Merger) may affect, either directly or indirectly, the ownership of
         Digex. No Company shall liquidate, wind up, or dissolve (or suffer any
         liquidation or dissolution), other than liquidations, wind ups, or
         dissolutions incident to mergers permitted under this SECTION 9.18. No
         Company may sell, assign, lease, transfer, or otherwise dispose of the
         capital stock (or other ownership interests) of any other




                                       5    FOURTH AMENDMENT TO CREDIT AGREEMENT
<PAGE>   6

         Company, except for sales, leases, transfers, or other such
         distributions to another Company or as permitted pursuant to and in
         accordance with SECTIONS 9.15 and 9.16(g). Any amendment or waiver to
         this SECTION 9.18 is subject to the express written consent of
         WorldCom."

         2.12     FINANCIAL COVENANTS. SECTION 9.32 is deleted in its entirety
and replaced with "INTENTIONALLY DELETED".

         2.13     DEFAULT. SECTION 10.9 is amended by deleting the "or"
immediately prior to CLAUSE (d) thereof and adding the following CLAUSE (e):

         "; or (e) WorldCom fails to pay when due (after lapse of any applicable
         grace periods) any Debt of WorldCom or any of its Subsidiaries (other
         than the Obligation or inter-Company Debt) in excess (individually or
         collectively) of $100,000,000."

         2.14     SCHEDULE 2.1. SCHEDULE 2.1 is deleted in its entirety and the
attached AMENDED SCHEDULE 2.1 shall be substituted therefor.

         2.15     EXHIBIT B-1. EXHIBIT B-1 is deleted in its entirety and the
attached AMENDED EXHIBIT B-1 shall be substituted therefor.

         2.16     EXHIBIT C-2. EXHIBIT C-2 attached hereto is added as
EXHIBIT C-2 to the Credit Agreement.

PARAGRAPH 3       AMENDMENT FEES. On the date hereof, Borrower shall pay to
Administrative Agent (for the ratable benefit of the Lenders other than TD), the
amendment fee described in that certain letter agreement dated as of October 31,
2000, between Borrower, Administrative Agent, and Lenders other than TD. The
failure of Borrower to comply with the provisions of this PARAGRAPH 3 shall
constitute a payment Default entitling Lenders to exercise their respective
Rights under the Loan Documents.

PARAGRAPH 4       CONDITIONS PRECEDENT. Notwithstanding any contrary provisions,
this Amendment is not binding upon the parties until the date (the "EFFECTIVE
DATE") upon which (a) the representations, acknowledgments, and ratifications in
this Amendment are true and correct, (b) Administrative Agent receives
counterparts of this Amendment executed by Borrower, Guarantors (other than
WorldCom), and Lenders; (c) Administrative Agent receives written evidence in
form and terms acceptable to Administrative Agent that either (i) to the extent
required pursuant to the Merger Agreement, or other related documents, WorldCom,
Inc. has consented to the terms of this Amendment, or (ii) no consent of
WorldCom, Inc. to any portion of this Amendment is required under the Merger
Agreement or other related documents; (d) Administrative Agent receives a
Guaranty executed by WorldCom, Inc.; (e) Administrative Agent receives an
executed Digex Limited Guaranty; (f) Borrower has paid to Administrative Agent
the amendment fees required to be paid to Lenders pursuant to PARAGRAPH 3
hereof; and (g) Borrower pays all unpaid and reasonable costs, fees, and
expenses of Administrative Agent's counsel incurred in connection with the Loan
Documents, including without limitation, any costs, fees, and expenses in
connection with the negotiation, preparation, delivery, and execution of this
Amendment and any related documents. From and after the Effective Date, TD shall
cease to be a Lender and shall have no further Rights as a Lender under the
Credit Agreement and the other Loan Documents, other than any such Rights or
obligations that would have expressly survived a termination of the Credit
Agreement and the other Loan Documents on the Effective Date.

PARAGRAPH 5       ACKNOWLEDGMENT AND RATIFICATION. As a material inducement to
Administrative Agent and the Lenders to execute and deliver this Amendment,
Borrower and each Guarantor (other than WorldCom) (a) consent to the agreements
in this Amendment and (b) agree and acknowledge that the execution, delivery,




                                       6    FOURTH AMENDMENT TO CREDIT AGREEMENT
<PAGE>   7

and performance of this Amendment shall in no way release, diminish, impair,
reduce, or otherwise affect the respective obligations of Borrower or Guarantors
under their respective Collateral Documents, which Collateral Documents shall
remain in full force and effect, and all Liens, guaranties, and Rights
thereunder are hereby ratified and confirmed.

PARAGRAPH 6       REPRESENTATIONS. As a material inducement to Lenders to
execute and deliver this Amendment, Borrower and each Guarantor (other than
WorldCom) represent and warrant to Lenders (with the knowledge and intent that
Lenders are relying upon the same in entering into this Amendment) that as of
the Effective Date of this Amendment and as of the date of execution of this
Amendment, (a) all representations and warranties in the Loan Documents are true
and correct in all material respects as though made on the date hereof and on
the Effective Date, except to the extent that (i) any of them speak to a
different specific date or (ii) the facts on which any of them were based have
been changed by transactions contemplated or permitted by the Loan Documents or
by this Amendment, and (b) except as waived by the other Loan Documents, no
Potential Default or Default exists.

PARAGRAPH 7       EXPENSES. Borrower shall pay all costs, fees, and expenses
paid or incurred by Administrative Agent incident to this Amendment and the Loan
Documents, including, without limitation, the reasonable fees and expenses of
Administrative Agent's counsel in connection with the negotiation, preparation,
delivery, and execution of this Amendment and any related documents.

PARAGRAPH 8       MISCELLANEOUS. This Amendment is a "Loan Document" referred
to in the Credit Agreement, and the provisions relating to Loan Documents in
SECTIONS 1 and 13 of the Credit Agreement are incorporated in this Amendment by
reference. Unless stated otherwise (a) the singular number includes the plural
and vice versa and words of any gender include each other gender, in each case,
as appropriate, (b) headings and captions may not be construed in interpreting
provisions, (c) this Amendment must be construed, and its performance enforced,
under New York law, (d) if any part of this Amendment is for any reason found to
be unenforceable, all other portions of it nevertheless remain enforceable, and
(e) this Amendment may be executed in any number of counterparts with the same
effect as if all signatories had signed the same document, and all of those
counterparts must be construed together to constitute the same document. The
execution, delivery, and effectiveness of this Amendment shall not, except as
expressly provided herein, operate as a waiver of any Rights of the Lenders
under the Credit Agreement or any Loan Documents, nor constitute a waiver under
the Credit Agreement or any other provision of the Loan Documents.

PARAGRAPH 9       ENTIRETIES. THIS AMENDMENT REPRESENTS THE FINAL AGREEMENT
BETWEEN THE PARTIES ABOUT THE SUBJECT MATTER OF THIS AMENDMENT AND MAY NOT BE
CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL
AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE
PARTIES.

PARAGRAPH 10      PARTIES. This Amendment binds and inures to Borrower,
Administrative Agent, Lenders, Guarantors (other than WorldCom), and their
respective successors and assigns.

         The parties hereto have executed this Amendment in multiple
counterparts on the date stated on the signature pages hereto, but effective as
of Effective Date.

                     [REMAINDER OF PAGE INTENTIONALLY BLANK.
                            SIGNATURE PAGES FOLLOW.]




                                       7    FOURTH AMENDMENT TO CREDIT AGREEMENT
<PAGE>   8

         Signature Page to that certain Fourth Amendment dated as of the date
first set forth above, among Intermedia Communications Inc., as Borrower, Bank
of America, N.A., as Administrative Agent, and Lenders.

                                      INTERMEDIA COMMUNICATIONS INC.

                                      By:
                                          --------------------------------------
                                          Raymond L. Lawless, Vice President and
                                          Treasurer

















                                              SIGNATURE PAGE TO FOURTH AMENDMENT
<PAGE>   9

         Signature Page to that certain Fourth Amendment dated as of the date
first set forth above, among Intermedia Communications Inc., as Borrower, Bank
of America, N.A., as Administrative Agent, and Lenders.

                                 BANK OF AMERICA, N.A., as Administrative Agent,
                                 and as a Lender

                                 By:
                                     -------------------------------------------
                                     Charles E. Brinley, Vice President
























                                              SIGNATURE PAGE TO FOURTH AMENDMENT
<PAGE>   10

         Signature Page to that certain Fourth Amendment dated as of the date
first set forth above, among Intermedia Communications Inc., as Borrower, Bank
of America, N.A., as Administrative Agent, and Lenders.

                                  THE BANK OF NEW YORK,
                                  as a Lender

                                  By:
                                      -----------------------------------------
                                      Geoffrey C. Brooks, Senior Vice President

























                                              SIGNATURE PAGE TO FOURTH AMENDMENT
<PAGE>   11

         Signature Page to that certain Fourth Amendment dated as of the date
first set forth above, among Intermedia Communications Inc., as Borrower, Bank
of America, N.A., as Administrative Agent, and Lenders.

                                         TORONTO DOMINION (TEXAS), INC.,
                                         as a Lender

                                         By:
                                             -----------------------------
                                             Ann S. Slanis, Vice President

























                                              SIGNATURE PAGE TO FOURTH AMENDMENT
<PAGE>   12

         Signature Page to that certain Fourth Amendment dated as of the date
first set forth above, among Intermedia Communications Inc., as Borrower, Bank
of America, N.A., as Administrative Agent, and Lenders.

         Each of the undersigned Guarantors hereby acknowledges that it has
reviewed this Amendment and agrees that certain of the representations and
covenants apply to Guarantors:

INTERMEDIA COMMUNICATIONS OF VIRGINIA INC.
INTERMEDIA CAPITAL INC.
INTERMEDIA LICENSING COMPANY
BUSINESS INTERNET, INC.
SHARED TECHNOLOGIES FAIRCHILD TELECOM, INC.
SHARED TECHNOLOGIES FAIRCHILD, INC.
ACCESS NETWORK SERVICES, INC.
SHARED TECHNOLOGIES FAIRCHILD COMMUNICATIONS CORP.
ACCESS VIRGINIA, INC.
NETWAVE SYSTEMS, INC.
EXPRESS COMMUNICATIONS, INC.
NATIONAL TELECOMMUNICATIONS OF FLORIDA, INC.
NTC, INC.
INTERMEDIA SERVICES LLC
ICI CAPITAL INC.

By:
    --------------------------------------------
    Raymond L. Lawless, Vice President
    and Treasurer
    (for all of the above referenced guarantors)

INTERMEDIA INVESTMENT, INC.

By:
    --------------------------------------------
    Raymond L. Lawless, President and
    Treasurer


















                                              SIGNATURE PAGE TO FOURTH AMENDMENT
<PAGE>   13

         Signature Page to that certain Fourth Amendment dated as of the date
first set forth above, among Intermedia Communications Inc., as Borrower, Bank
of America, N.A., as Administrative Agent, and Lenders.

         Each of the undersigned Guarantors hereby acknowledges that it has
reviewed this Amendment and agrees that certain of the representations and
covenants apply to Guarantors:

                                   DIGEX, INCORPORATED

                                   By:
                                       -----------------------------------------
                                       T. Scott Zimmerman, Vice President

                                   DIGEX INTERNATIONAL HOLDING COMPANY

                                   By:
                                       -----------------------------------------
                                       Timothy M. Adams, Chief Financial Officer


















                                              SIGNATURE PAGE TO FOURTH AMENDMENT
<PAGE>   14

                              AMENDED SCHEDULE 2.1

                             LENDERS AND COMMITMENTS
                        (Intermedia Communications Inc.)

NAME AND ADDRESS OF LENDERS              COMMITMENT        COMMITMENT PERCENTAGE
---------------------------           ---------------      ---------------------

Bank of America, N.A.                 $175,000,000.00              50.00%
Communications Finance Division
Attn: Charles E. Brinley
901 Main Street, 64(th) Floor
Dallas, Texas 75202
214/290-0950
214/290-9390 (fax)

The Bank of New York                  $175,000,000.00              50.00%
Attn: Brendan T. Nedzi
One Wall Street
New York, NY 10286
212/635-8628
212/635-8593 (fax)

                 Totals               $350,000,000.00             100.00%













                                                            AMENDED SCHEDULE 2.1
<PAGE>   15

                               AMENDED EXHIBIT B-1

                            FORM OF BORROWING NOTICE
                        (Intermedia Communications Inc.)

                      ____________________________, ______

Bank of America, N.A.
      as Administrative Agent for the
      Lenders as defined in the Credit
      Agreement referred to below
Bank of America Plaza, 14(th) Floor
901 Main Street
Dallas, TX 75202
Attn: Ruth De La Garza
      Fax: (214) 209-2118

         Reference is made to the Revolving Credit Agreement, dated as of
December 22, 1999 (as amended, modified, supplemented, or restated from time to
time, the "Credit Agreement"), among the undersigned, as Borrower, the Lenders
party thereto, Administrative Agent, Banc of America Securities LLC, as Sole
Lead Arranger and Book Manager, BNY Capital Markets, Inc., as Syndication Agent,
Toronto Dominion (Texas), Inc. ("TD"), as Documentation Agent, and Bank of
America, N.A., The Bank of New York, and TD, as Arranging Agents. Capitalized
terms used herein and not otherwise defined herein shall have the meanings
assigned to such terms in the Credit Agreement. The undersigned hereby gives you
notice pursuant to the Credit Agreement that it requests a Borrowing under the
Credit Agreement, and in that connection, sets forth below the terms on which
such Borrowing is requested to be made:

<TABLE>
<CAPTION>

                                                                           REVOLVER    TELECOMMUNICATIONS
                                                                           FACILITY         FACILITY
                                                                           --------    ------------------
<S> <C>                                                                    <C>         <C>
(A) Specify if Borrowing is under Revolver Facility or Telecommunications
    Facility. (If under Telecommunications Facility, specify the
    Telecommunications Loan Effective Date to which such Borrowing
    relates.)

(B) Borrowing Date(*)

(C) Amount of Borrowing(**)

(D) Type of Borrowing(***)

(E) For a Eurodollar Rate Borrowing, the Interest Period and the last day
    thereof(****)
</TABLE>

         Borrower hereby certifies that the following statements are true and
correct on the date hereof, and will be true and correct on the Borrowing Date
specified herein after giving effect to such Borrowing:

                  (a)     The requested Borrowing will not cause the Principal
         Debt to exceed the Total Commitment; if the Borrowing is a Borrowing
         under the Revolver Facility, the Borrowing will not cause the Revolver
         Principal Debt to exceed the Revolver Commitment; if the Borrowing is a
         Borrowing under the Telecommunications Facility, such Borrowing will
         not (i) cause the Telecommunications Principal Debt to exceed the
         Telecommunications Commitment, and (ii) cause the Telecommunications
         Principal Debt under the applicable Telecommunications Loan to exceed
         the aggregate commitments of the Lenders for such Telecommunications
         Loan;




                                                             AMENDED EXHIBIT B-1
<PAGE>   16

                  (b)     All of the representations and warranties of any
         Company set forth in the Loan Documents are true and correct in all
         material respects (except to the extent that (i) the representations
         and warranties speak to a specific date or (ii) the facts on which such
         representations and warranties are based have been changed by
         transactions contemplated or permitted by the Loan Documents and, if
         applicable, supplemental Schedules have been delivered with respect
         thereto and, when necessary, approved by Required Lenders);

                  (c) $___________________ of the requested Borrowing is to be
         used for ______________________; $_________________ is to be used
         for ________________________; and $_________________ is to be used
         for ________________________.

                  (d)      No material adverse change in the financial
         conditions, operations, or businesses of the Companies has occurred
         since the date of the quarterly and audited annual financial statements
         most recently delivered by Borrower to Lenders pursuant to SECTIONS 7.1
         and 9.3(a) and (b) of the Credit Agreement;

                  (e)      If the requested Borrowing is under the
         Telecommunications Facility, the Telecommunications Principal Debt
         shall not exceed 80% of the cost of the acquisition or construction of
         the applicable Telecommunications Assets financed thereby, and such
         acquisition has not been and shall not be funded from any other source;

                  (f)      No Default or Potential Default has occurred and is
         continuing or will arise after giving effect to the requested
         Borrowing; and

                  (g)      If the requested Borrowing is to finance a Permitted
         Acquisition, Borrower has complied with and delivered (or shall comply
         with or deliver on or prior to the date of the requested Borrowing) the
         items required by SECTION 7.2 and SCHEDULE 7.2.

                                      Very truly yours,

                                      INTERMEDIA COMMUNICATIONS INC.

                                      By
                                         -----------------------------------
                                      (Name)
                                            --------------------------------
                                      (Title)
                                             -------------------------------

By execution below, WorldCom acknowledges and consents to the requested
Borrowing:

                                      WORLDCOM, INC.

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

Rate:
      ----------------

Confirmed by:
              ----------------------------

(*)      Must be a Business Day occurring prior to the Termination Date and (a)
         must be at least three Business Days following receipt by
         Administrative Agent of this Form of Borrowing Notice for any
         Eurodollar Portion, and (b) can be the same Business Day for any Base
         Rate Borrowing, so long as received by Administrative Agent by 12:00
         p.m. Dallas, Texas time.




                                                             AMENDED EXHIBIT B-1
<PAGE>   17

(**)     Not less than $5,000,000 or a greater integral multiple of $1,000,000
         (if a Eurodollar Rate Borrowing) or $1,000,000 or a greater integral
         multiple of $100,000 (if a Base Rate Borrowing).

(***)    Eurodollar Rate Borrowing or Base Rate Borrowing.

(****)   1, 2, 3, or 6 months, or other periods requested by Borrower to the
         extent available from Lenders -- in no event may the Interest Period
         end after the Termination Date.




















                                                             AMENDED EXHIBIT B-1