Prospectus Supplement No. 7 Filed Pursuant to Rule 424(b)(3)
(To Prospectus Dated November 2, 1999) Registration No. 333-89345
Prospectus Supplement
Dated January 28, 1999
This prospectus relates to the resale by the holder of our:
o $300,000,000 principal amount of 6.25% convertible notes due
2009,
o $425,500,000 principal amount at maturity of 2.25% convertible
notes due 2009, and
o the shares of Class A common stock issuable upon conversion of
the notes.
This prospectus supplement should be read in conjunction with, and may
not be delivered or utilized without, the prospectus dated November 2, 1999,
including any amendments or supplements thereto. The terms of the notes are set
forth in the prospectus.
The information in the table appearing under the heading "Selling
Securityholders" on page 42 in the prospectus is hereby amended by adding the
information below with respect to selling securityholders not previously listed
in the prospectus or in any amendments or supplements thereto, and by
superceding the information with respect to selling securityholders previously
listed in the prospectus or in any amendments or supplements thereto that are
listed below:
<TABLE>
<CAPTION>
Principal Number of
Amount at Shares of Class Percentage of
Maturity of Percentage of A Common Stock Number of Class A
6.25% Notes 6.25% Notes Issuable Upon Shares of Common Stock
Beneficially Outstanding as Conversion of Class A Outstanding
Owned That of January26, the 6.25% Notes Common Stock as of January
Selling Securityholders May Be Sold 1999 That May Be Sold Owned 26, 1999**
----------------------- ----------- ---- ---------------- ----- ----------
Owned
<S> <C> <C> <C> <C> <C>
Amoco Corporation Master Trust for $2,600,000 1.48 106,557 -- *
Employee Pension Plans
Delphi Foundation, Inc. $16,000 * 655 -- *
General Motors Employees Global $3,766,000 2.14 154,344 21,600 *
Group Pension Trust
General Motors Foundation, Inc. $164,000 * 6,721 -- *
Motors Insurance Corporation $804,000 * 32,950 -- *
======== ======= ======= ======= =======
TOTAL $7,350,000 4.18 301,227 21,600 *
<CAPTION>
Principal Number of
Amount at Shares of Class Percentage of
Maturity of Percentage of A Common Stock Number of Class A Common
2.25% Notes 2.25% Notes Issuable Upon Shares of Stock
Beneficially Outstanding as Conversion of Class A Outstanding as
Owned That of January 26, the 2.25% Notes Common Stock of January 26,
Selling Securityholders May Be Sold 1999 That May Be Sold Owned 1999**
----------------------- ----------- ---- ----------- ----- ----
<S> <C> <C> <C> <C> <C>
STI Capital Management $500 * 20 -- *
<FN>
* Less than 1%.
** Includes shares issuable upon conversion of the notes and shares beneficially
owned as of January 26, 2000.
</FN>
</TABLE>