NewMarket Corporation Notes Credit Upgrade 

Richmond, VA, March 2, 2010 – NewMarket Corporation (NYSE – NEU) President and Chief Executive Officer, Thomas E. Gottwald, commented today on the recent upgrades to the company’s credit ratings. 

Mr. Gottwald noted that Moody’s has upgraded NewMarket’s rating to Ba1 with a stable outlook while S&P has upgraded their rating to BB+, with a stable outlook. 

Moody’s stated that, “The rating upgrade is supported by NewMarket’s strong cash flow generation, improvements in gross margins and EBITDA margins and modest leverage for the rating category.”  S&P stated that, “The upgrade follows improved financial metrics and liquidity as the company generated strong profits and cash flows during 2009.”

Mr. Gottwald stated, "We are very pleased that the credit agencies have raised our ratings to reflect the improvements we have made in our business, our cash flows and resultant balance sheet. Over the past decade, we have broadened our product lines and geographic presence, and by developing state of the art products to help our customers grow their business, we have been rewarded with the strong earnings and financial strength that has led to these upgrades. We are excited about our future and look forward to generating more value for our shareholders.” 

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.

Some of the information contained in this press release constitutes forward-looking statements 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 materially from expectations include, but are not limited to:  changes in the demand for our products; increases in product cost and our ability to increase prices; timing of sales orders; gain or loss of significant customers; competition from other manufacturers and resellers; resolution of environmental liabilities; significant changes in new product introduction; the impact of fluctuations in foreign exchange rates on reported results of operations; changes in various markets; geopolitical risks in certain of the countries in which we conduct business; changes in credit market conditions; and other factors detailed from time to time in the reports that NewMarket files with the Securities and Exchange Commission, including the risk factors in Item 1A,  “Risk Factors”  of our 2009 Annual Report on  Form 10-K, which is available to shareholders upon request. 

You should keep in mind that any forward-looking statement made by NewMarket in the foregoing discussion speaks only as of the date on which such forward-looking statement is made.  New risks and uncertainties come up from time to time, and it is impossible for us to predict these events or how they may affect the company.  We have no duty to, and do not intend to, update or revise the forward-looking statements in this discussion after the date hereof, except as may be required by law.  In light of these risks and uncertainties, you should keep in mind that the events described in any forward-looking statement made in this discussion, or elsewhere, might not occur.  

 David A. Fiorenza
 Investor Relations
 Phone: 804.788.5555
 Fax:  804.788.5688