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                                                                     Exhibit 4.4

                            CERTIFICATE OF AMENDMENT
                                       OF
                    CERTIFICATE OF DESIGNATION OF SERIES AND
                    DETERMINATION OF RIGHTS AND PREFERENCES
                                       OF
                      SERIES C CONVERTIBLE PREFERRED STOCK
                                       OF
                              CAIS INTERNET, INC.



     CAIS Internet, Inc., a corporation organized and existing under and by
virtue of the General Corporation Law of the State of Delaware (the
"Corporation"), does hereby certify:

     FIRST:  The Certificate of Designation of Series and Determination of
Rights and Preferences of Series C Convertible Preferred Stock of the
Corporation is hereby amended by striking Section 5(d)(i)(D)(5) thereof and by
substituting in lieu of said paragraph the following:


          "(5)  pursuant to warrants issued by the Company pursuant to (a) the
                                    Warrant Agreement, dated as of September 4,
                                    1998, among the Company, Cleartel
                                    Communications, Inc., CAIS, Inc., and ING
                                    (U.S.) Capital Corporation, Inc. (the "ING
                                    Warrant Agreement"); (b) the Series A
                                    Preferred Stock and Warrant Purchase
                                    Agreement, dated as of February 19, 1999,
                                    among the Company and the several purchasers
                                    set forth therein; (c) the Warrant to
                                    Purchase Common Stock granted to Hilton
                                    Hotels Corporation; and (d) the Common Stock
                                    Warrant, dated as of October 27, 1999, among
                                    the Company and U.S. Telesource, Inc."


     SECOND:  The amendment to the Certificate of Designation of Series and
Determination of Rights and Preferences of Series C Convertible Preferred Stock
of the Corporation herein
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certified has been duly adopted by the Board of Directors of the Corporation in
accordance with the provisions of Section 141 of the General Corporation Law of
the State of Delaware.

     THIRD:  The amendment to the Certificate of Designation of Series and
Determination of Rights and Preferences of Series C Convertible Preferred Stock
of the Corporation herein certified has been duly adopted by the written consent
of the Series C Preferred Stockholders of the Corporation in accordance with the
provisions of Sections 228 and 242 of the General Corporation Law of the State
of Delaware.

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     IN WITNESS WHEREOF, CAIS INTERNET, INC. has caused this Certificate of
Amendment of Certificate of Designation of Series and Determination of Rights
and Preferences of Series C Convertible Preferred Stock to be signed by its
President this 27th day of October, 1999.

                                             CAIS INTERNET, INC.



                                             By:  /s/ William M. Caldwell, IV
                                                  ---------------------------
                                                  William M. Caldwell, IV
                                                  President







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