Exhibit 99.1


FOR IMMEDIATE RELEASE                         CONTACT: JAMES P. KELLY
                                                    Director, Investor Relations
                                                    (617) 342-6244
                                                    jim_kelly@cabot-corp.com

                                                    Ethel Shepard
                                                    Corporate Affairs Manager
                                                    (617) 342-6254
                                                    ethel_shepard@cabot-corp.com


CABOT CORPORATION ACQUIRES ASSETS OF SUPERIOR MICROPOWDERS, LLC

BOSTON, MA (June 2, 2003) - Cabot Corporation (CBT/NYSE) announced today that it
has purchased the assets of Superior MicroPowders, LLC (SMP), a privately-held
company located in Albuquerque, New Mexico. SMP is an advanced materials
development and manufacturing company with proprietary nano- and micro- powder
production systems and manufacturing capability. While in the development stage,
SMP has been working with several major companies to develop particle
applications for use in the electronics, fuel cell, display, and other markets.

The purchase price for the acquisition was approximately $16 million. Cabot
believes that a significant portion of the purchase price will be allocated to
in-process research and development, which is required to be immediately charged
to expense.

Barry Neal has been named General Manager of the SMP organization. Previously,
Mr. Neal was the Director, Research and Development, Cabot Supermetals, located
in Boyertown, PA. For the past year, Mr. Neal has led the integration of Cabot
Supermetals, in Japan.



SMP was founded in 1997 by Dr. Toivo Kodas and Dr. Mark Hampden-Smith, two
leaders in the field of aerosol processing of materials. Both Dr. Hampden-Smith
and Dr. Kodas, as technical directors, will continue to lead the efforts to
integrate SMP technology into Cabot.

Kennett F. Burnes, Cabot Chairman and CEO said, "We are excited about the
expertise and technology that SMP brings because it will allow Cabot to continue
expanding our technology to areas that complement our existing markets and
provide opportunities for future new business growth. This acquisition of SMP is
consistent with Cabot's strategy to expand our business portfolio into high
value-added markets."

For more information on SMP, please go to www.superiormicropowders.com.

                               About Cabot

Cabot Corporation is a global specialty chemicals and materials company and is
headquartered in Boston, MA. Cabot's major products are carbon black, fumed
silica, inkjet colorants, and capacitor materials. Cabot has approximately 4,500
employees in 45 manufacturing plants located in 23 countries around the world.
Further information is available on the Company's web site at
www.cabot-corp.com.

FORWARD-LOOKING INFORMATION: Included above are forward-looking statements
relating to management's expectations of future profits, the possible
achievement of the Company's financial goals and objectives and management's
expectations for shareholder value creation initiatives and for the Company's
product development program. Actual results may differ materially from the
results anticipated in the forward-looking statements included in this press
release due to a variety of factors, including market supply and demand
conditions, fluctuations in currency exchange rates, costs and availability of
raw materials, patent rights of others, stock market conditions, demand for our
customers' products, competitors' reactions to market conditions, the outcome of
pending litigation and governmental investigations, the impact of global health
and safety



concerns on economic conditions or market opportunities and other factors
discussed in the Company's 2002 Annual Report on Form 10-K. Timely
commercialization of products under development by the Company may be disrupted
or delayed by technical difficulties, market acceptance, competitors' new
products, as well as difficulties in moving from the experimental or development
stage to the production stage.