<PAGE>   1
EXHIBIT 99.1

E.SPIRE COMMUNICATIONS, INC.
SUPPLEMENTAL FINANCIAL INFORMATION
YEAR TO DATE - DECEMBER 31, 1999
($'S IN THOUSANDS)

<TABLE>
<CAPTION>
                                            Networks Placed           Networks Placed            Networks Placed
                                             in Service                 in Service                  in Service
                                           Prior to 12/31/95            During 1996                During 1997
                                       ------------------------   ------------------------   -------------------------
<S>                                      <C>                         <C>                         <C>
Property, Plant & Equipment               $            175,077        $           145,130         $           178,872

Revenues                                  $             58,203        $            41,676         $            41,092

EBITDA                                    $             10,866        $             1,799         $            (8,800)

EBIT                                      $             (2,861)       $            (8,572)        $           (22,968)

Network Statistics (cumulative)
-------------------------------
      Access Lines Installed                            69,476                     40,760                      49,050
      Fiber Miles                                       46,882                     42,072                      45,622
      Route Miles                                          784                        494                         398
      Buildings Connected                                1,703                        931                       1,304
      Voice Grade Equivalents                          822,089                    438,743                     555,075
</TABLE>

<TABLE>
<CAPTION>
                                          Networks Placed           Networks Placed
                                            in Service                in Service
                                            During 1998               During 1999                Total
                                       ----------------------   -----------------------   -------------------
<S>                                      <C>                        <C>                      <C>
Property, Plant & Equipment               $           57,320         $         132,397        $      688,796

Revenues                                  $            7,267         $           1,314        $      149,552

EBITDA                                    $         (14,086)         $         (8,213)        $     (18,433)

EBIT                                      $          (18,641)        $         (14,451)       $      (67,492)

Network Statistics (cumulative)
-------------------------------
      Access Lines Installed                           4,933                     1,071               165,290
      Fiber Miles                                     24,823                    17,100               176,499
      Route Miles                                        159                       335                 2,169
      Buildings Connected                                210                         1                 4,149
      Voice Grade Equivalents                         74,813                    12,330             1,903,050
</TABLE>