KMC TELECOM HOLDINGS, INC.

                         CERTIFICATE OF AMENDMENT TO THE
                    CERTIFICATE OF THE POWERS, DESIGNATIONS,
                     PREFERENCES AND RIGHTS OF THE SERIES A
                        CUMULATIVE CONVERTIBLE PREFERRED
                         STOCK, PAR VALUE $.01 PER SHARE

                     Pursuant to Sections 141 and 242 of the
                General Corporation Law of the State of Delaware

      As contemplated by Sections 141 and 242 of the General  Corporation Law of
the State of Delaware (the "DGCL"), the following resolution was duly adopted by
the Board of Directors  of KMC Telecom  Holdings,  Inc., a Delaware  corporation
(the "Corporation"), by unanimous written consent, dated a June 28, 2000:

     WHEREAS,  the Board of Directors of the  Corporation is authorized,  within
the limitations and  restrictions  stated in the Certificate of Incorporation of
the  Corporation,  to propose by resolution or resolutions  for the amendment of
outstanding  series  of  preferred  stock,  par  value  $.01 per  share,  of the
Corporation,  to contain such voting powers,  full or limited, or without voting
powers, and such designations, preferences and relative, participating, optional
or other special  rights,  and  qualifications,  limitations or  restrictions as
shall be stated and expressed in the resolution or resolutions providing for the
amendment  thereof adopted by the Board of Directors,  and as are not stated and
expressed  in the Amended and  Restated  Certificate  of  Incorporation,  or any
amendment  thereto,  including  (but  without  limiting  the  generality  of the
foregoing)  such  provisions as may be desired  concerning  voting,  redemption,
dividends, dissolution, or the distribution of assets and such other subjects or
matters as may be fixed by resolution or  resolutions  of the Board of Directors
under the DGCL.

     WHEREAS,  the  Board  of  Directors  of the  Corporation,  pursuant  to its
authority under Section 242 of the DGCL, deems it advisable to further amend the


<PAGE>

terms of the Certificate of the Powers, Designations,  Preferences and Rights of
the Series A Cumulative  Convertible  Preferred Stock, Par Value $.01 per Share,
dated as of  November  4, 1997,  as  previously  amended  (the  "Certificate  of
Designation").

     WHEREAS,  the  holders of  two-thirds  of the shares of Series A  Preferred
Stock  outstanding,  voting as a separate class,  have approved the amendment of
the terms of the Certificate of Designation as set forth herein.  Unless defined
otherwise herein,  all capitalized terms shall have the meaning given to them in
the Certificate of Designation.

     NOW, THEREFORE, BE IT RESOLVED:

1.    Exceptions to Conversion Price Adjustment.  Section 5(f) is deleted in its
      entirety and replaced with the following:

            "(f) Exceptions to Conversion Price Adjustment.  Notwithstanding the
            foregoing,  no  adjustment  to the  Conversion  Price  shall be made
            pursuant to this Section 5 in connection with the grant, issuance or
            sale of Common Stock, Convertible Securities,  warrants,  options or
            other  rights  to  subscribe   for  or  purchase   Common  Stock  or
            Convertible  Securities:  (i) pursuant to employee stock purchase or
            stock  option   ownership  plans  adopted  by  the  Corporation  for
            employees,  consultants  and/or directors of the Corporation and its
            affiliates;   (ii)   pursuant  to  the  terms  of  any   Convertible
            Securities,  warrants,  options or other rights to subscribe  for or
            purchase granted, issued or sold pursuant to clause (i) above; (iii)
            pursuant to the High Yield Debt and Equity Offering (as defined in a
            Subordinated Loan and Security Agreement,  dated as of September 22,
            1997,  among KMC Telecom  Inc.  ("KMC") and KMC Telecom II, Inc. and
            AT&T Commercial  Finance  Corporation,  as in effect on the Series C
            Preferred Stock Issue Date) or a subsequent debt offering  occurring
            prior to  December  31,  1998;  (iv)  pursuant  to the  terms of any
            Convertible  Securities,   warrants,  options  or  other  rights  to
            subscribe for or purchase granted, issued or sold pursuant to clause
            (iii) above; (v) pursuant to Section 10C of the Amended and Restated
            Note  Purchase  and  Investment  Agreement,  dated as of October 22,
            1996,  as  amended,  by and among the  Corporation,  Nassau  Capital
            Partners L.P., NAS Partners I L.L.C.  and Harold N. Kamine;  or (vi)
            pursuant  to  the  issuance  of  Series  C  Cumulative   Convertible
            Preferred Stock and Series D Cumulative  Convertible Preferred Stock
            pursuant  to a  Purchase  Agreement,  by and among the  Corporation,
            General Electric Capital  Corporation,  CoreStates  Holdings,  Inc.,
            Nassau Capital Partners L.P., NAS Partners I L.L.C. and the issuance
            of any shares of Common Stock issued in conversion thereof; provided
            that the  aggregate  number  of shares  of  Common  Stock  issued or
            issuable pursuant to clauses (i) and (ii) above shall not exceed 25%
            of the Common Stock (on a Fully Diluted basis) outstanding from time
            to time and the aggregate number of shares of Common Stock issued or

                                       2
<PAGE>

            issuable  pursuant  to clause  (iii) and (iv) above shall not exceed
            11% of the Common Stock (on a Fully Diluted basis)  outstanding from
            time to time."

2.    Voting Rights.  Section  6(c)(vii) is deleted in its entirety and replaced
      with the following:

            "(vii)  authorize  or  enter  into  any  transaction  or  series  of
            transactions  (excluding  transactions authorized by the Corporation
            or its subsidiaries prior to the Series A Preferred Stock Issue Date
            and any  amendments  thereto that do not alter the economic value of
            such  transactions)  with any director or  executive  officer of the
            Corporation  or any Person  directly or indirectly  controlling  the
            Corporation (or any affiliate thereof other than a subsidiary of the
            Corporation) if the aggregate amount involved in such transaction or
            series of transactions involves the payment by or to the Corporation
            or its  subsidiaries of more than $100,000 in any one fiscal year of
            the Corporation,  provided,  however, that transactions or series of
            transactions which involve any type of payment or grant of salary or
            compensation to any director or executive officer of the Corporation
            or any Person directly or indirectly  controlling the Corporation or
            any affiliate thereof,  excluding any subsidiary of the Corporation,
            shall not be  subject  to this  restriction  nor the  provisions  of
            Section 6(c) hereof; or"


                                       3
<PAGE>

      IN WITNESS WHEREOF, KMC TELECOM HOLDINGS, INC. has caused this certificate
to be duty executed by its Chief Financial Officer this 29th day of June, 2000.



                                   KMC TELECOM HOLDINGS, INC.


                                   By:  /s/William H. Stewart
                                        ------------------------------------
                                        Name:  William H. Stewart
                                        Title: Chief Financial Officer