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                                                                    EXHIBIT 11.3



                            ALLEGIANCE TELECOM, INC.
                    COMPUTATION OF PER SHARE EARNINGS (LOSS)
                        THREE MONTHS ENDED JUNE 30, 1999
                (Dollars in thousands, except per share amounts)


<TABLE>
<CAPTION>
                                                                    Number of Shares   Percent Outstanding      Equivalent Shares
                                                                    ----------------   --------------------     -----------------
<S>                                                                       <C>                       <C>            <C>
Prior to Initial Public Offering
     1997 Common Stock Offering                                                  639                100.00%                   639

After Initial Public Offering
     1998 Common Stock Offering                                           15,000,000                100.00%            15,000,000
     Preferred Stock Converted to Common Stock                            60,511,692                100.00%            60,511,692
     1999 Common Stock Offering                                           21,041,100                 78.61%            16,539,360
     Treasury Shares                                                         (37,968)               100.00%               (37,968)
     Warrants Exercised                                                      383,240                 68.43%               262,254
     Stock Options Exercised                                                  44,030                 50.92%                22,418
     Employee Stock Discount Purchase Plan Shares Issued                     100,844                 98.51%                99,336
                                                                                                                   --------------

WEIGHTED AVERAGE SHARES OUTSTANDING                                                                                    92,397,731

NET LOSS APPLICABLE TO COMMON STOCK                                                                                $  (49,256,000)

NET LOSS PER SHARE, BASIC AND DILUTED                                                                              $        (0.53)
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</TABLE>



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