Prospectus Supplement No. 2 Filed Pursuant to Rule 424(b)(3) (To Prospectus Dated November 2, 1999) Registration No. 333-89345 Prospectus Supplement Dated December 2, 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: Principal Percentage Number of Shares Amount at of 6.25% of Class A Percentage of Maturity of Notes Common Stock Number of Class A Common 6.25% Notes Outstanding Issuable Upon Shares of Stock Beneficially as of Conversion of the Class A Outstanding as Owned That December 1, 6.25% Notes That Common of December 1, Selling Securityholders May Be Sold 1999 May Be Sold Stock Owned 1999** ----------------------- ----------- ---------- ----------------- ----------- -------------- Allstate Insurance Company $ 3,750,000 1.41 153,688 -- * Associated Electric & Gas Insurance Services $ 1,000,000 * 40,983 -- * Limited BNP Arbitrage SNC $ 4,500,000 1.69 184,426 -- * Continental Assurance Company $ 5,600,000 2.10 229,508 -- * Global Bermuda Limited Partnership $ 1,000,000 * 40,983 -- * Lakeshore International, Ltd $ 2,000,000 * 81,967 -- * Putnam Convertible Income-Growth Trust $ 3,000,000 1.12 122,950 -- * Tribeca Investments LLC $ 6,500,000 2.44 266,393 -- * =========== ===== ========= ======== ====== TOTAL $27,350,000 10.25 1,120,898 0 * Principal Percentage Number of Shares Amount at of 2.25% of Class A Percentage of Maturity of Notes Common Stock Number of Class A Common 2.25% Notes Outstanding Issuable Upon Shares of Stock Beneficially as of Conversion of the Class A Outstanding as Owned That December 1, 2.25% Notes That Common of December 1, Selling Securityholders May Be Sold 1999 May Be Sold Stock Owned 1999** ----------------------- ----------- ---------- ----------------- ----------- -------------- J.P. Morgan Securities Inc. $ 5,000,000 1.38 208,333 -- * The TCW Group, Inc. $67,015,000 18.48 2,792,291 -- 1.90 =========== ===== ========= ======== ====== TOTAL $72,015,000 19.86 3,000,624 0 2.03* Less than 1%. ** Includes shares issuable upon conversion of the notes and shares beneficially owned as of December 2, 1999.