Exhibit 99.1

Cabot Corp Reports Second Quarter Adjusted EPS of $0.96 and Diluted EPS of $3.70

Adjusted EPS improvement of 68% year on year driven by record segment profits

BOSTON--(BUSINESS WIRE)--May 1, 2012--Cabot Corporation (NYSE: CBT) today announced results for its second quarter of fiscal 2012.

Key Highlights

• Margin expansion and solid volumes in Rubber Blacks and Performance Segment contribute to strong results
• Indonesia and China capacity expansions completed and ready to serve end market demand
• New products launched for adhesives, batteries and coatings markets
• Diluted EPS of $3.70 includes gain on sale of the Supermetals Business

Commenting on the results, Cabot President and CEO Patrick Prevost, said, “We are very pleased with our second quarter results. Our Rubber Blacks Business and Specialty Fluids Segment set new records of quarterly EBIT performance. The execution of our strategy continues to deliver results and we are making great strides towards achieving our $4.50 adjusted EPS target in 2014.”

Prevost continued, “Through the implementation of new commercial agreements, stronger sequential volumes, a favorable product mix and robust Specialty Fluids Segment earnings, we achieved strong performance this quarter. In addition, we completed important capacity expansion and energy efficiency projects and introduced a number of innovative products to the market. We also finalized the sale of the Supermetals Business and recorded a substantial gain during the quarter. I am extremely pleased with the performance year to date and continue to be excited about the future of this company.”

Financial Detail

For the second quarter of fiscal 2012, net income attributable to Cabot Corporation was $240 million ($3.70 per diluted common share), which includes $2.92 per share of income from discontinued operations related to the sale of the Supermetals Business. In addition, net income includes a per share charge of $0.18, principally for restructuring costs and tax related items. Adjusted EPS for the second quarter of fiscal 2012 was $0.96 per share.

Segment Results

Core Segment -- Second quarter fiscal 2012 EBIT in the Rubber Blacks Business increased by $21 million compared to the same quarter of fiscal 2011, principally driven by higher prices and a favorable product mix. These positive factors more than offset the impact of 2% lower volumes and higher raw material costs. Sequentially, EBIT increased $17 million driven by higher prices, a favorable product mix and 4% higher volumes.

Global and regional volume changes for the Core Segment for the second quarter of fiscal 2012 as compared to the same quarter of the prior year and the first quarter of fiscal 2012 are included in the table below:

Performance Segment -- Second quarter fiscal 2012 EBIT in the Performance Segment decreased by $4 million compared to the second quarter of fiscal 2011. The decrease was driven principally by higher fixed costs from the start-up of new capacity and the unfavorable impact of declining inventory levels. Volumes in Fumed Metal Oxides increased 4%, while Performance Products volumes increased 1%. Sequentially, Performance Segment EBIT increased by $14 million, principally due to higher volumes from increases in end market demand as customers returned to more normalized purchasing levels. Volumes in Fumed Metal Oxides increased by 17% sequentially, and volumes in Performance Products increased 14%.

Specialty Fluids -- For the second quarter of fiscal 2012, EBIT in the Specialty Fluids Segment increased by $15 million compared to the second quarter of fiscal 2011 and by $11 million compared to the first quarter of fiscal 2012. The EBIT increases in both periods resulted principally from higher rental revenues from larger, more complex jobs that were longer in duration as well as a favorable sales mix driven by a significant product sale during the quarter.

New Business Segment -- For the second quarter of fiscal 2012, EBIT in the New Business Segment decreased by $4 million compared to the second quarter of fiscal 2011 and was flat compared to the first quarter of fiscal 2012. Sequentially, revenue improved in all businesses. However, sequential EBIT was flat due to higher fixed costs related to a planned shutdown at our aerogel plant. Year-over-year EBIT declined due the absence of $3 million of business development milestone revenue recorded in the prior year in our Cabot Elastomer Composites Business and lower commercial activity in our Aerogel Business.

Cash Performance -- The Company ended the second quarter of fiscal 2012 with a cash balance of $366 million, an increase of $178 million from the first quarter of fiscal 2012. The increase in cash was driven by strong operating results and the receipt of $175 million for the first payment related to the sale of the Supermetals Business. These items were partially offset by capital expenditures of $56 million and an increase in net working capital of $31 million.

Taxes -- During the second quarter of fiscal 2012, the Company recorded a net tax provision of $23 million, including a net discrete tax benefit of $1 million. The tax rate on continuing operations was 30% for the second quarter of fiscal 2012. Excluding the impact of certain items, the operating tax rate on continuing operations for the quarter was 26%.

Outlook

Commenting on the outlook for the Company, Prevost said, “We are optimistic about the improving conditions in North America and China. We continue to see attractive growth in the emerging economies of Asia and South America, both in the short and long-term. The growth in emerging markets is seen not only in the tire and automotive industries, but across a variety of the industries we serve. The European macroeconomic environment, however, remains challenging. While the quarterly EBIT fluctuations in our Specialty Fluids Segment will continue due to the project nature of the business, we are pleased with our expansion into new geographies with new customers.”

Prevost continued, “We are delivering earnings growth through margin and capacity expansion as well as new business and product development. Our increased margins were achieved through continual efficiency improvement efforts and the execution of our global pricing strategy. We commissioned new production capacity in recent months and we expect further growth investments to be ready for production in the coming quarters. Our portfolio of new products and businesses continues to strengthen. I remain confident in our ability to achieve our long-term financial targets of $4.50 adjusted EPS in 2014 while maintaining adjusted ROIC over 13%.”

Earnings Call

The Company will host a conference call with industry analysts at 2:00 p.m. Eastern time on Wednesday, May 2, 2012. The call can be accessed through Cabot’s investor relations website at http://investor.cabot-corp.com.

Cabot Corporation, headquartered in Boston, Massachusetts, is a global specialty chemicals and performance materials company. Cabot’s major products are carbon black, fumed silica, cesium formate drilling fluids, inkjet colorants and aerogels. The Company’s website address is: http://www.cabotcorp.com.

Forward-Looking Statements -- This earnings release contains forward-looking statements based on management’s current expectations, estimates and projections. All statements that address expectations or projections about the future, including our ability to meet our long-term financial targets, strategy for growth, demand for our products, and when we expect new production capacity to be available are forward-looking statements. Some of the forward-looking statements may be identified by words like “expects,” “anticipates,” “plans,” “intends,” “projects,” “indicates,” and similar expressions. Forward-looking statements are based on our current expectations, assumptions, estimates and projections about Cabot's businesses and strategies, market trends and conditions, economic conditions and other factors. These statements are not guarantees of future performance and are subject to risks, uncertainties, potentially inaccurate assumptions, and other factors, some of which are beyond our control and difficult to predict. If known or unknown risks materialize, or should underlying assumptions prove inaccurate, our actual results could differ materially from past results and from those expressed in the forward-looking statement. Important factors that could cause our results to differ materially from those expressed in the forward-looking statements include, but are not limited to changes in raw material costs; costs associated with the research and development of new products, including regulatory approval and market acceptance; competitive pressures; delays in the successful integration of structural changes, including restructuring plans, and joint ventures; delays in the completion or start-up of our capacity expansion projects; the laws, regulations, policies and economic conditions, including inflation, interest and foreign currency exchange rates, of countries in which the company does business; and severe weather events that cause business interruptions, including plant and power outages, or disruptions in supplier or customer operations. These factors are discussed more fully in the reports we file with the Securities and Exchange Commission, particularly our latest annual report on Form 10-K.

Explanation of Terms Used -- The term “operating tax rate” represents the tax rate on our recurring operating results. This rate excludes discrete tax items, which are unusual or infrequent items that are excluded from the estimated annual effective tax rate and other tax items, including the impact of the timing of losses in certain jurisdictions, cumulative rate adjustment and the impact of certain items on both operating income and tax provision.

The term “product mix” refers to the various types and grades, or mix, of products sold in a particular Business or Segment during the period, and the positive or negative impact of that mix on the revenue or profitability of the Business or Segment.

When we discuss the profitability impact of changes in inventory levels, we refer to the recording of fixed manufacturing costs on either our balance sheet or through our consolidated statement of operations. When inventories increase, we record fixed manufacturing costs on our balance sheet, causing lower fixed costs to be recorded in the consolidated statement of operations and benefiting the recorded profitability of the business. When inventories decrease, the opposite occurs, and additional fixed costs flow through the consolidated statement of operations, unfavorably affecting recorded business profitability.

Use of Non-GAAP Financial Measures -- The preceding discussion of our results and the accompanying financial tables report adjusted EPS and Total segment earnings before interest and taxes, “Total Segment EBIT”, which are non-GAAP financial measures. Our chief operating decision-maker uses adjusted EPS and Total Segment EBIT to evaluate the performance of the Company in terms of profitability. We believe that these measures also assist our investors in evaluating the changes in our results and the Company's performance.

In calculating adjusted EPS, we exclude from our net income per share from continuing operations certain items of expense and income that management does not consider representative of the Company's ongoing operations. Adjusted EPS should be considered as supplemental to, and not as a replacement for, EPS determined in accordance with GAAP. A reconciliation of adjusted EPS to EPS from continuing operations, the most directly comparable GAAP financial measure, and the certain items that are excluded from our calculation of adjusted EPS, are provided in the table titled "Certain Items and Reconciliation of Adjusted EPS.”

Total Segment EBIT is a non-GAAP performance measure, and should not be considered an alternative for Income (loss) from continuing operations before taxes, the most directly comparable GAAP financial measure. In calculating Total Segment EBIT, we exclude “certain items”, meaning items that management does not consider representative of our fundamental segment results, as well as items that are not allocated to our business segments, such as interest expense and other corporate costs. Our Chief Operating Decision Maker uses segment EBIT to evaluate the operating results of each segment and to allocate resources to the segments. We believe that this non-GAAP measure provides useful supplemental information for our investors as it is an important indicator of the Company’s operational strength and performance. Investors should consider the limitations associated with this non-GAAP measure, including the potential lack of comparability of this measure from one company to another. A reconciliation of Total Segment EBIT to Income (loss) from continuing operations before income taxes and equity in net earnings of affiliate companies is provided in the table titled, “Summary Results by Segments.”