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                                                                    EXHIBIT 10.4

                        AMENDMENT TO EMPLOYMENT AGREEMENT

            THIS IS AN AMENDMENT (the "AMENDMENT") to that certain Employment
Agreement (the "AGREEMENT"), dated as of the 25th day of April, 2002 by and
among MPOWER COMMUNICATIONS CORP., a Nevada corporation (the "COMPANY"), and S.
Gregory Clevenger ("EXECUTIVE"). Terms defined in the Agreement and not
otherwise defined herein have the meaning given to them in the Agreement.

            The Company and Executive, for and in consideration of the promises,
terms and conditions contained herein, do hereby agree to make the following
amendments to the Agreement.

            1. Section 1 of the Agreement is amended, in its entirety, to read
as follows:

            "EMPLOYMENT TERM. Subject to earlier termination in accordance with
            the provisions hereof, this Agreement, as modified by as amendment
            dated as of September 18, 2002 (the "AMENDMENT") shall become
            effective as of the date of the Amendment (the "EFFECTIVE DATE") and
            the term of your employment with the Mpower Communications
            Corporation (the "COMPANY") pursuant to this Agreement (the "TERM")
            shall expire on September 18, 2003; provided, however, that the Term
            shall automatically be extended for an additional one-year period on
            September 18, 2003 (the "EXTENSION DATE") unless at least 60 days
            prior to the Extension Date, either party shall give notice to the
            other in accordance with this Agreement of a desire not to extend
            the Term."

            2. Section 3.01 of the Agreement is amended to delete the phrase
"$225,000" in the second line thereof and replace it with the phrase "$300,000."

            3. Section 3.04 of the Agreement is deleted in its entirety, and is
replaced by the following:

            "(a) Not later than September 18, 2002 (the "GRANT DATE"), Executive
            shall be granted stock options to purchase 100,000 shares of the
            Company's common stock (the "NEW OPTIONS"). Such New Options shall
            (i) have an exercise price equal to $.22 per share, (ii) vest in
            three (3) equal installments on each of the first three
            anniversaries of the Grant Date, (iii) have a term (the "TERM") of
            (10) years from the Grant Date, (iv) remain exercisable, to the
            extent vested on the Termination Date, for five (5) years after the
            termination of Executive's employment with the Company for any
            reason, but in no event after the expiration of the Term, and (v) be
            non-qualified options within the meaning of the Internal Revenue
            Code.

            (b) All of Executive's unexercised stock options as of the Effective
            Date, other than the New Options (the "EXISTING OPTIONS") shall be
            amended so that they remain exercisable, to the extent vested on the
            Termination Date, for five (5)
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            years after the termination of Executive's employment with the
            Company for any reason, but in no event later than 10 years after
            the date they were granted."

            4. Section 4.02 of the Agreement, from sub-section (ii) through the
end of the paragraph, is amended read as follows:

            "(ii) a severance benefit (the "SEVERANCE BENEFIT") equal to two
            times (a) the Fixed Salary immediately preceding the Termination
            Date and (b) the "HIGHEST BONUS", where the Highest Bonus equals the
            greater of the Annual Bonus paid by the Company to Executive (x)
            during the twelve (12) month period immediately preceding the
            Termination Date, or (y) during the twelve (12) month period
            immediately preceding the Effective Date"); provided, however, that
            Executive shall have no right to have paid or payable from the Trust
            adopted by Company on October 23, 2001 pursuant to a Trust Agreement
            with HSBC Bank USA as . trustee (the "OLD TRUST"), any portion of
            his Severance Benefit (i) attributable to any increase in
            Executive's Fixed Salary after March 31, 2002, or (ii) otherwise in
            excess of the Severance Benefit or other severance payment that
            Executive would have been eligible to receive if his employment with
            the Company had terminated as of March 31, 2002 under circumstances
            entitling him to a Severance Benefit or other severance payment.
            Payment of the Severance Benefit shall be contingent upon
            Executive's execution of a waiver and release of claims (a
            "RELEASE") in favor of the Company and its affiliates and their
            respective employees and agents, substantially in the form set forth
            in Appendix A." The Severance Benefit shall be paid by the Company
            in a lump-sum, no later than two (2) business days after the
            expiration of the Revocation Period, as defined in the Release."

            5. Section 4.04 of the Agreement is deleted in its entirety, and
Section 6 of the Agreement is amended to add the following to the definition of
"Good Reason":

            "(iii) any resignation by Executive, for any reason, occurring not
            earlier than 90 days or later than 270 days after a Change of
            Control; and (iv) the relocation of Executive's principal place of
            business to a location that is more than 35 miles from Executive's
            principal place of business on the Effective Date.

                  For the purposes of this Agreement, a "CHANGE OF CONTROL"
            shall be deemed to have occurred if: (i) by any method, transaction,
            or series of related transactions, more than 50% of the outstanding
            shares of the Company or beneficial ownership thereof are acquired
            by persons other than the members of the Board, those persons who
            were more than 5% stockholders of the Company prior to the Effective
            Date, employees of the Company and any of their immediate family
            members and affiliates, and there is a change in the membership of
            the Board, such that fewer than 50% of the members of the Board are
            persons who served in such position prior to the change in
            ownership; (ii) there is a merger or consolidation of the Company in
            which the Company is not the continuing or surviving entity or
            pursuant to which the Company's shares are converted into cash,
            securities or other property; or (iii) the Company sells, leases or
            exchanges


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            all or substantially all of its assets or the Company's stockholders
            approve the liquidation or dissolution of the Company."

            6. Miscellaneous. Except as modified this Amendment, all terms and
conditions of the Agreement shall remain in full force and effect. It is the
intention of the parties hereto that if this Amendment is void, becomes
voidable, or otherwise is or becomes unenforceable as drafted, then the
Agreement shall continue in full force and effect, in accordance with the terms
and conditions thereof immediately prior to the execution of this Amendment.
This Amendment may be executed in any number of counterparts which together
shall constitute one instrument, shall be governed by and construed in
accordance with the laws and decisions of the State of New York applicable to
contracts made and to be performed therein without giving effect to the
principles of conflict of laws.


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            IN WITNESS WHEREOF, the parties have duly executed this Agreement as
of this 20th day of September , 2002.

                                         MPOWER COMMUNICATIONS CORP.

                                         By: /s/ Rolla P. Huff
                                             ----------------------------------
                                             Rolla P. Huff
                                             Chairman and CEO


                                             /s/ S. Gregory Clevenger
                                             ----------------------------------
                                             S. Gregory Clevenger



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