<PAGE> 1
Filed Pursuant to Rule 424(b)(3)
Registration No. 333-86257
SUPPLEMENT, DATED AUGUST 4, 2000, TO PROSPECTUS, DATED SEPTEMBER 17, 1999, OF
UNITEDGLOBALCOM, INC.
Additional Selling Securityholder. The following selling securityholder is added
to the list of selling securityholders in the prospectus:
<TABLE>
<CAPTION>
NUMBER OF DEPOSITARY SHARES
---------------------------
NAME OF SELLING SECURITYHOLDER OWNED OFFERED
------------------------------ ----- -------
<S> <C> <C>
Associated Electric & Gas Insurance Services Limited. ........ 8,000 8,000
</TABLE>
