Ceradyne Announces Exercise of Over-Allotment Options for 270,000 Shares of Common Stock and $11 Million of Senior Subordinated Convertible Notes.

COSTA MESA, Calif. -- Ceradyne, Inc. (Company) (Nasdaq:CRDN) announced today that the underwriters of the Company's public offering of shares of its common stock have exercised their over-allotment option in full to purchase an additional 270,000 shares. Including the sale of these additional shares, which is scheduled to close today, the total number of shares sold by the Company in this offering will be 2,070,000. All of the shares were offered by the Company.

The Company also announced today that the underwriters of the Company's public offering of 2.875% senior subordinated convertible notes due 2035 have also exercised their over-allotment option in full to purchase an additional $11 million aggregate principal amount of the notes. Including the sale of these additional notes, which is scheduled to close today, the aggregate principal amount of 2.875% senior subordinated convertible notes due 2035 sold by the Company in this offering will be $121 million.

The notes are convertible by holders into shares of the Company's common stock at an initial conversion rate of 17.1032 shares of common stock per $1,000 principal amount of notes (which represents an initial conversion price of approximately $58.47 per share, subject to adjustment). The notes are convertible only under certain circumstances, including if the price of the Company's common stock reaches, or the trading price of the notes falls below, specified thresholds, if the notes are called for redemption, if specified corporate transactions or fundamental changes occur, or during the 10 trading days prior to maturity of the notes. The Company may redeem the notes at any time after December 20, 2010.

The common stock offering and senior subordinated convertible note offering were conducted as separate public offerings by means of separate prospectus supplements.

Citigroup Corporate and Investment Banking, Needham & Company, LLC and Wachovia Securities acted as joint book-running managers of the common stock offering and Adams Harkness, Inc., JMP Securities LLC and Wedbush Morgan Securities Inc. acted as co-managers. Information about this offering is available in the prospectus supplement for the common stock offering filed with the Securities and Exchange Commission. Copies of the prospectus supplement can be obtained from Citigroup Corporate and Investment Banking, Attn: Prospectus Department, Brooklyn Army Terminal, 140 58th Street, 8th Floor, Brooklyn, NY 11220, [phone], Needham & Company, LLC, 445 Park Avenue, Third Floor, New York, NY 10022, [phone], or Wachovia Securities, Attn: Equity Capital Markets, 7 St. Paul Street, Baltimore, MD 21202.

Citigroup Corporate and Investment Banking acted as sole book-running manager of the senior subordinated convertible note offering. Wachovia Securities and Needham & Company, LLC acted as co-lead managers of the offering. Information about this offering is available in the prospectus supplement for the senior subordinated convertible note offering filed with the Securities and Exchange Commission. Copies of the prospectus supplement can be obtained from Citigroup Corporate and Investment Banking, Attn: Prospectus Department, Brooklyn Army Terminal, 140 58th Street, 8th Floor, Brooklyn, NY 11220, [phone].

The Company used a portion of the net proceeds from the initial closings of these offerings, which were completed on December 19, 2005, to repay all outstanding debt under its credit facility, which was $110.9 million as of September 30, 2005. The balance of the net proceeds from the initial closings and from the sale of the over-allotment securities will be used for working capital, capital expenditures and other general corporate purposes, including to fund potential acquisitions of businesses, technologies or product lines.

A registration statement relating to these securities has been filed with and declared effective by the Securities and Exchange Commission. This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

Ceradyne develops, manufactures and markets advanced technical ceramic products and components for defense, industrial, automotive/diesel and commercial applications.

Except for the historical information contained herein, this news release contains forward-looking statements regarding future events and the future performance of Ceradyne that involve risks and uncertainties that could cause actual results to differ materially from those projected. Words such as "anticipates," "believes," "plans," "expects," "intends," "future," and similar expressions are intended to identify forward-looking statements. These risks and uncertainties are described in the supplemental prospectuses described above, as filed with the Securities and Exchange Commission, and the documents included or incorporated by reference therein.