NewMarket Corporation Schedules Conference Call and Webcast to Review First Quarter 2005 Financial Results 
Richmond, VA—April 27, 2005--NewMarket Corporation (NYSE: NEU) announced today it will release first quarter 2005 earnings at the close of business on Wednesday, May 4, 2005.  The earnings announcement will also be available on the company’s website at beginning May 5, 2005.  A conference call and Internet webcast is scheduled for 10:00 a.m. EDT on Friday, May 6 to review first quarter 2005 results. 

You can access the conference call live by dialing 877-407-8031 (domestic) or  201-689-8031 (international) and requesting the NewMarket conference call.  To avoid delays, callers should dial in five minutes early.  The call will also be broadcast via the Internet and can be accessed through the Company’s website at or   A teleconference replay of the call will be available until May 9, 2005  by dialing 877-660-6853 (domestic) and 201-612-7415 (international).  The account number is 286.  The conference ID number is 150305.  A webcast replay will be available for 30 days.

NewMarket Corporation through its subsidiaries, Afton Chemical Corporation and Ethyl Corporation, develops, manufactures, blends, and delivers chemical additives that enhance the performance of petroleum products. From custom-formulated chemical blends to market-general additive components, the NewMarket family of companies provides the world with the technology to make fuels burn cleaner, engines run smoother and machines last longer.

Forward-Looking Statement
Some of the information contained in this press release constitutes forward-looking comments within the meaning of the Private Securities Litigation Reform Act of 1995.  Although NewMarket’s management believes its expectations are based on reasonable assumptions within the bounds of its knowledge of its business and operations, there can be no assurance that actual results will not differ materially from expectations.  Factors that could cause actual results to differ from expectations are included in NewMarket’s (Ethyl’s) latest annual report on Form 10-K, which is available upon request.


     NewMarket Corporation, Richmond
     Investor Relations: David A. Fiorenza, 804-788-5555
     Fax: 804-788-5688