SHARES OF COMMON STOCK ISSUABLE UPON NUMBER OF CONVERSION OF PREFERRED PREFERRED SELLING HOLDERS SECURITIES SECURITIES - --------------------------------------------------------------- --------- ------------------- Alexandra Global Investment Fund, 1 Hol........................ 105,000 72,261 Allegheny Teledyne Inc. Pension Plan........................... 65,000 44,733 Argent Classic Convertible Arbitrage Fund (Bermuda) L.P........ 25,000 17,205 Argent Classic Convertible Arbitrage Fund L.P.................. 25,000 17,205 Arkansas PERS (1).............................................. 6,000 4,129 Bond Fund Series -- Oppenheimer Bond Fund for Growth........... 100,000 68,820 Chase Securities Inc........................................... 539,900 371,559 Cincinnati Insurance Company................................... 75,000 51,615 Daniel H. Renberg and Associates, Inc. on behalf of accounts managed by it................................................ 15,600 10,736 Donaldson Lufkin & Jenrette Securities Corp.................... 70,000 48,174 Eric Indemnity Co. Attorney in fact for Eric Insurance Exchange..................................................... 40,000 27,528 Fiduciary Trust Company International.......................... 59,500 40,948 Forum Capital Markets LP....................................... 25,000 17,205 Franklin Investors Securities Trust -- Convertible Securities Fund......................................................... 10,000 6,882 Golden Rule Insurance Company.................................. 59,000 40,604 Hamilton Partners Limited...................................... 200,000 137,640 Hermitage Insurance Company.................................... 30,000 20,646 Hughes & Sheila Potiker Family Foundation...................... 5,000 3,441 ICI American Holdings Pension Trust (1)........................ 2,000 1,376 JP Morgan Securities Incorporated.............................. 186,050 128,040 L.A. Fire and Police Pension Plan.............................. 240,000 165,168 Mark IV Industries, Inc. and Subsidiaries Master Trust......... 5,000 3,441 McMahan Securities Company, L.P................................ 15,000 10,323 MFS Convertible Securities Fund -- a series of MFS Series Trust I............................................................ 25 17 MFS Total Return Fund, a series of MFS Series Trust V.......... 8,000 5,506 Nalco Chemical Retirement (1).................................. 3,100 2,133 Oak Tree Partners, L.P......................................... 192,000 132,134 Olin Foundation................................................ 6,000 4,129 Pitney Bowes Retirement Fund................................... 68,000 46,798 PRIM Board (1)................................................. 10,000 6,882 Prudential Securities.......................................... 222,000 152,780 Queensway International Indemnity Company...................... 10,000 6,882 Reliant Trading................................................ 35,410 24,369 Robertson Stephens & Co., L.L.P................................ 33,000 22,711 SAIF Corporation (1)........................................... 10,000 6,882 San Diego City Retirement/Nicholas Applegate................... 8,100 5,574 SBC Warburg Inc. (1)........................................... 20,000 13,764 Shepard Investments International Ltd.......................... 56,500 38,883 Shepard Trading Limited........................................ 39,590 27,246 Stark International............................................ 56,500 38,883 Starvest Discretionary (1)..................................... 2,500 1,721 State of Delaware Retirement-Froley, Revy (1).................. 5,000 3,441 State of Oregon Equity (1)..................................... 10,000 6,882 Swiss Bank Corporation London Branch (1)....................... 285,000 196,137 The Common Fund................................................ 25,000 17,205 UBS Securities LLC............................................. 460,400 316,847 ZENECA Holdings Pension Trust (1).............................. 2,000 1,376 TOTALS............................................... 3,471,175 2,388,863

- --------------- (1) In addition to the securities included in the related prospectus with respect to such holders. The date of the related Prospectus is June 26, 1997.