EXHIBIT K



                            Joint Filing Agreement



          In accordance with Rule 13d-1(k) under the Securities Exchange Act of
1934, the undersigned hereby agree to the joint filing with each other on behalf
of each of them of this Amendment No. 1 to Schedule 13D (including amendments
thereto) with respect to the Class A Common Stock, $0.01 par value per share,
and the Common Stock, $0.01 par value per share, of Prodigy Communications
Corporation, and that this Agreement be included as an Exhibit to such joint
filing.  This Agreement may be executed in any number of counterparts all of
which taken together shall constitute one and the same instrument.

          IN WITNESS WHEREOF, the undersigned hereby execute this Agreement this
9th day of June, 2000.


                         SBC COMMUNICATIONS INC.



                         By:            /s/ James S. Kahan
                                 -----------------------------------
                         Name:   James S. Kahan
                         Title:  Senior Executive Vice President - Corporate
                                 Development


                         SBC INTERNET COMMUNICATIONS, INC.



                         By:            /s/ Stephen A. McGaw
                                 -----------------------------------
                         Name:   Stephen A. McGaw
                         Title:  President