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                                                                   EXHIBIT 10.18
[LOGO] DIGEX(SM)
       BUSINESS INTERNET
---------------------------------------------
DIGEX Incorporated           800.99DIGEX
6800 Virginia Manor Road     301.847.5000
Beltsville, Maryland 20705   Fax 301.847.5017
                             www.digex.net

September 11, 1996

Mr. Bobby Patrick
7726 Old Ox Road
Fairfax Station, Virginia 22039

Dear Bobby,

On behalf of DIGEX, Inc., I am pleased to offer you the position of Manager, NT
Server Operations, reporting to Bill Webb, in the Server Product business unit.
Your start date is September 9, 1996. Key components of this offer are as
follows:

Base Salary:             $65,000 Annually

Benefits:                All aspects of the employee benefits program are
                         covered in separate benefit policies describing various
                         programs available at DIGEX.

Bonus:                   20% bonus paid annually. The bonus will be based upon
                         metrics to be determined by Bill Webb.

Department:              Server

Employment Verification: On your first day you will need to provide Human
                         Resources with two forms of identification, proving
                         that you are eligible to work in the United States.
                         Employment and Payroll begins on the date of full
                         compliance. Please refer to the attached federal list
                         of acceptable identification.

Stock:                   Subject to Board of Directors approval you will be
                         granted 10,000 options at market price.

We are sincerely excited about you filling the position of Manager, NT Server
Operations and look forward to you becoming a part of the DIGEX family.

Sincerely,
                                           /s/  Robert Patrick
                                          ----------------------------
/s/ William F. Webb                        Accepted: Bobby Patrick

Bill Webb                                       9/30/96
VP, Technical Operations                  ----------------------------
                                            Date
cc: Dave Mann
    Director of Human Resources
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Digex keeps e-business in business(SM)         [LOGO] digex(SM)

                                                            One Digex Plaza
                                                            Beltsville, MD 20705
                                                            www.digex.com

                                                            301.847.5000
                                                            Fax 301.847.5215




                                    July 9, 1999



Mr. Robert B. Patrick
One Digex Plaza
Beltsville, Maryland 20705

Dear Bobby:

          This will confirm the changes we have agreed upon in your employment
arrangement with Digex as follows:

          (a) Your base salary is $150,000 per year and your annual bonus
opportunity is 40% of your base salary.

          (b) If the Digex initial public offering of common stock becomes
effective, you will receive options to purchase an aggregate of 100,000 shares
of Digex common stock, of which 50% will be exercisable at a price equal to
$5.00 per share and the balance will be exercisable at a price equal to the
initial public offering price. Options covering 25% of the shares will vest one
year following the date of grant and the balance will vest in equal quarterly
installments thereafter.

          (c) Following the occurrence of a change of control of Digex, all
unvested installments of the options will vest if your employment is terminated
by Digex (other than for cause as defined herein) or, if earlier, one year
following the date of occurrence of the change of control if you continue to be
employed by Digex at that time. In addition, if your employment is terminated by
Digex for any reason other than for cause prior to one year from the date of
this letter, 25% of the shares covered by your option[s] will immediately vest
upon the date of termination.

          (d) Your existing Intermedia stock options shall continue in full
force and effect following consummation of the initial public offering of Digex
common stock.

          For purposes of this letter:

          "Change of Control" means: the sale, exchange or transfer of common
          stock of
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Digex keeps e-business in business(SM)         [LOGO] digex(SM)

                                                            One Digex Plaza
                                                            Beltsville, MD 20705
                                                            www.digex.com

                                                            301.847.5000
                                                            Fax 301.847.5215

             Intermedia or of Digex, whether in one transaction or a series of
             related transactions occurring within one year, which results in an
             accumulation of 50% or more of the outstanding shares of common
             stock (on a fully diluted basis) of Intermedia or of Digex in one
             holder or several affiliated holders (or any such transaction(s)
             occurring within six months that result in an accumulation of at
             least 35% of such shares of common stock (on a fully diluted
             basis)) or an event involving the sale or merger of Intermedia or
             of Digex or their respective assets which results in the holders of
             shares of common stock immediately prior to the occurrence of such
             sale or merger holding less than a majority of the outstanding
             shares of common stock immediately thereafter.

             "Cause" means: (i) any conduct or behavior by you that would
             reasonably be expected to have a material adverse affect on
             Intermedia's or Digex's business or reputation, (ii) commission by
             you of an act involving moral turpitude or dishonesty, including
             fraud, (iii) your material failure to reasonably perform your
             duties for Digex or (iv) your willful failure to perform or abide
             by any lawful directions or instructions of Digex consistent with
             your capacity as a senior executive of Digex.

             Except as amended hereby, the terms of your employment continue in
   full force and effect. If the foregoing is acceptable to you, please sign in
   the space provided below and return to me one fully executed copy of this
   letter. Nothing in this letter will be deemed to affect the at will status of
   your continued employment by Digex.

                                          DIGEX, INCORPORATED



                                          By: /s/  Mark Shull
                                             ----------------------------------
                                             Mark Shull, President and Chief
                                               Executive Officer

Agreement with terms
of letter confirmed:


 /s/  Robert Patrick
-------------------------
    Robert B. Patrick