<PAGE>
Filed Pursuant to Rule 424(b)(3)
Registration No. 333-44058
Common Shares in the form of Shares or American Depositary Shares
CARRIER1 INTERNATIONAL S.A.
PROSPECTUS SUPPLEMENT DATED NOVEMBER 17, 2000
TO PROSPECTUS DATED OCTOBER 20, 2000
The Selling Shareholders table on pages 34 - 35 of the prospectus is
hereby amended to update the information to include (or update information as
to) the following persons as selling shareholders in the prospectus and to list
their respective amounts of shares beneficially owned:
<TABLE>
<CAPTION>
Shares Beneficially Number of Shares to
Owned Prior to the Offering be Sold in the
Selling Shareholder Number Percentage Offering
------------------- ------ ---------- --------
<S> <C> <C> <C>
Merrill Lynch International Ltd. 219,340 *
Ospizio Israelitico Osp.(( S. Saadun)) 2,637 *
Remington Investment Strategies, L.P. 18,788 *
The Nikko Trust and Banking Corporation 3,355 *
</TABLE>
