KMC TELECOM HOLDINGS, INC.

                         CERTIFICATE OF AMENDMENT TO THE
                    CERTIFICATE OF THE POWERS, DESIGNATIONS,
                     PREFERENCES AND RIGHTS OF THE SERIES C
                        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 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
terms of the Certificate of Powers, Designations,  Preferences and Rights of the
Series C 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 C
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;  or (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;  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
            issuable  pursuant to clauses  (iii) and (iv) above shall not exceed
            11% of the Common Stock (on a Fully Diluted basis)  outstanding from
            time to time."



<PAGE>

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 C 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"



                                       2
<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