Crompton Corporation Announces Annual Meeting and First Quarter 2005 Earnings Conference Calls.

MIDDLEBURY, Conn. -- Crompton Corporation (NYSE: CK) will release first quarter 2005 earnings on April 26 before the New York Stock Exchange opens. Copies of the release as well as informational slides will be available on the Investor Relations section at www.cromptoncorp.com. In addition, Crompton will host two teleconferences on April 26:

--The first, at 11:15 a.m. EDT, will be a listen-only broadcast of the 2005 Annual Meeting of Stockholders, which will include a business overview and first quarter earnings summary;

--The second, at 2:00 p.m. EDT, will be an interactive question and answer call, which will include a very brief summary of first quarter results.

Detailed information for the two conference calls is as follows:

2005 Annual Meeting of Stockholders:

--11:15 a.m. EDT, in listen-only mode.

--Interested parties are asked to dial in approximately 10 minutes prior to the start time at [phone].

--Replay of the call will be available for two weeks starting at 2:45 p.m. on April 26. To access the replay, call [phone] and enter access code 778079.

First Quarter Earnings Q&A Teleconference:

--2:00 p.m. EDT.

--Interested parties are asked to dial in approximately 10 minutes prior to the start time at [phone].

--Replay of the call will be available for two weeks starting at 5:30 p.m. on April 26. To access the replay, call [phone] and enter access code 778081.

Live Internet access to both conference calls will be available through the Investor Relations section of the company's Web site. If you need further information pertaining to the call, please contact Lori Kim at [phone].

Crompton Corporation, with 2004 sales of $2.5 billion, is a producer and marketer of specialty chemicals and polymer products and equipment. Additional information concerning Crompton Corporation is available at www.cromptoncorp.com.