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Filed pursuant to Rule 424(b)(3)
Registration 333-86257
Supplement, Dated December 21 , 1999, to Prospectus, Dated September 17, 1999,
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of UnitedGlobalCom, Inc.
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Additional Selling Securityholders. The following selling securityholder is
added to the list of selling securityholders in the prospectus:
Number of Depositary Shares
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Name of Selling Securityholder Owned Offered
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AJG Financial Services Inc. 1,000 1,000
