National Oilwell Varco Has Refiled Hart-Scott-Rodino Premerger Notification

National Oilwell Varco (NYSE: NOV) announced today that it has withdrawn
and refiled its notification and report form filed under the
Hart-Scott-Rodino Antitrust Improvements Act of 1976 (HSR Act) in
connection with NOV′s proposal to acquire all of the outstanding shares
of Ameron International Corporation (NYSE: AMN) common stock. This
action was taken voluntarily by NOV in order to provide the Department
of Justice (DOJ) staff up to an additional 30 days to review the
proposed acquisition and determine whether to close its investigation or
issue a 'Second Request? for additional information.

NOV and Ameron remain committed to working cooperatively with the DOJ as
it conducts its review of the proposed transaction. NOV and Ameron
expect that the Closing could occur as early as the 4th quarter of 2011.

Ameron is a multinational manufacturer of highly-engineered products and
materials for the chemical, industrial, energy, transportation and
infrastructure markets. Ameron is a leading producer of
fiberglass-composite pipe for transporting oil, chemicals and corrosive
fluids, and specialized materials and products used in infrastructure
projects, such as poles and construction materials in Hawaii. Ameron is
also a leading provider of water transmission lines and fabricated steel
products, such as wind towers. Ameron operates businesses in North
America, South America, Europe and Asia, has a presence through
affiliated companies in the Middle East, and has approximately 2,900
employees and 25 manufacturing locations on a worldwide basis.

NOV is a worldwide leader in the design, manufacture and sale of
equipment and components used in oil and gas drilling and production
operations, the provision of oilfield services, and supply chain
integration services to the upstream oil and gas industry.

Statements made in this press release that are forward-looking in nature
are intended to be 'forward-looking statements? within the meaning of
the Private Securities Litigation Reform Act of 1995. Such statements
relate to a variety of matters, including but not limited to: the timing
and anticipated completion of the proposed transaction and other
statements that are not purely statements of historical fact. These
forward-looking statements are made on the basis of the current beliefs,
expectations and assumptions of the management of Ameron and NOV and are
subject to significant risks and uncertainty. Readers are cautioned not
to place undue reliance on any such forward-looking statements. All such
forward-looking statements speak only as of the date they are made, and,
except as required by law, neither Ameron nor NOV undertakes any
obligation to update or revise these statements, whether as a result of
new information, future events or otherwise.

Factors that could cause actual results to differ materially from the
forward-looking statements contained herein include, but are not limited
to: any operational or cultural difficulties associated with the
integration of the businesses of Ameron and NOV; potential adverse
reactions or changes to business relationships resulting from the
announcement or completion of the proposed transaction; unexpected
costs, charges or expenses resulting from the proposed transaction;
litigation or adverse judgments relating to the proposed transaction;
risks relating to the consummation of the contemplated transaction,
including the risk that the required stockholder approval might not be
obtained in a timely manner or at all or that other closing conditions
will not be satisfied; the failure to realize synergies and cost savings
from the transaction or delay in realization thereof; any difficulties
associated with requests or directions from governmental authorities
resulting from their reviews of the transaction; and any changes in
general economic and/or industry-specific conditions. Additional factors
that could cause actual results to differ materially from those
described in the forward-looking statements are set forth in the
documents filed respectively by Ameron and NOV with the Securities and
Exchange Commission (SEC), including Ameron′s Annual Report on Form 10-K
for the fiscal year ended November 30, 2010 and its Quarterly Report on
Form 10-Q for the fiscal quarter ended May 29, 2011, and NOV′s Annual
Report on Form 10-K for the fiscal year ended December 31, 2010, which
identify significant risk factors which could cause actual results to
differ from those contained in the forward-looking statements.

IMPORTANT ADDITIONAL INFORMATION WILL BE FILED WITH THE SEC

In connection with the proposed transaction, Ameron intends to file a
proxy statement and other relevant documents concerning the transaction
with the SEC. AMERON STOCKHOLDERS ARE URGED TO READ THE PROXY STATEMENT
AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC WHEN THEY BECOME
AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE
TRANSACTION. The proxy statement and other documents incorporated by
reference in the proxy statement will be available free of charge at the
SEC′s website at www.sec.gov
or by directing a request to Ameron International Corporation, 245 South
Los Robles Avenue, Pasadena, California 91101 Attention: Secretary.

Ameron and its directors and officers may be deemed participants in the
solicitation of proxies in connection with the proposed transaction.
Information about the directors and executive officers of Ameron is set
forth in Ameron′s most recent definitive proxy statement, which was
filed with the SEC on February 28, 2011. Certain directors and executive
officers of Ameron may have direct or indirect interests in the proposed
transaction that may be different from those of Ameron′s stockholders
generally. Investors may obtain additional information regarding such
interests by reading the proxy statement and other relevant documents
that Ameron will file with the SEC when they become available.

National Oilwell Varco, Inc.

Clay Williams, 713-346-7606

Clay.Williams@nov.com

or

Ameron
International Corporation

James S. Marlen, 626-683-4000

Chairman,
President and Chief Executive Officer

or

Gary Wagner,
626-683-4000

Senior Vice President, Chief Financial Officer