Basel, Switzerland and San Diego, California
December 4, 2002

Syngenta and Diversa today announced they have formed a broad collaboration to establish a shared biotechnology research platform and to discover products. Diversa is to acquire certain technology rights from Syngenta for pharmaceutical applications, in exchange for equity. The transaction will strengthen the research capabilities of both companies.

Research and product development alliance

• Syngenta and Diversa will combine their research activities in genomics and related technologies for new plant science applications, as well as for selected antibody generation and other biopharma product development.
• Syngenta will enter into a renewable research contract with Diversa for an initial commitment of $118 million over seven years to be invested in products in Syngenta's exclusive fields; Diversa will receive milestone payments and royalties on products developed.

Technology transaction

• Diversa will acquire an exclusive, royalty-free perpetual license from Syngenta for gene technology and intellectual property, including proteomics, metabolomics, RNA dynamics, fungal technologies, and bioinformatics, for use in the pharmaceutical field; as well as related assets.
• In exchange, Diversa will issue to Syngenta stock and warrants representing 14% and 3% respectively of Diversa's outstanding stock pro forma for the equity issuances, increasing Syngenta's ownership to over 18%. The warrants issued to Syngenta are exercisable for ten years starting in 2008 at an exercise price of $22.

Syngenta will relocate its plant genomics programs, including its pioneering work with the rice genome, from the Torrey Mesa Research Institute (TMRI) in La Jolla, California to Syngenta Biotechnology, Inc. (SBI) in Research Triangle Park, North Carolina. It is expected that the majority of employees will be relocated to Diversa or SBI.

"This collaboration will ensure that Syngenta stays at the cutting edge of genomics science and creates new product opportunities," said Dr. David Lawrence, Syngenta Head of Research & Technology. "The agreement enables us to broaden our biotechnology capability and bring innovative products to market more quickly."

"Syngenta has made a significant investment at TMRI in developing leading edge technologies and assembling a highly talented scientific organization," said Jay M. Short, Ph.D., Diversa President and Chief Executive Officer. "This transaction provides Diversa with complementary technologies that will accelerate our pharmaceutical product development programs."

Since 1999, Syngenta and Diversa have been collaborating through their Zymetrics joint venture on the development of enhanced animal feed. Zymetrics is forecasting its first product launch in 2004.

The transaction is expected to be completed early in 2003, and is subject to the approval of the FTC under Hart-Scott-Rodino as well as approval of Diversa shareholders. A proxy statement for Diversa's shareholder meeting will be filed with the SEC shortly. Diversa shareholders holding about 32 percent of the stock have agreed to vote in favor of the transaction. Diversa will grant Syngenta registration rights to the stock and warrants it will receive.

Diversa Corporation (Nasdaq: DVSA) is a leader in applying proprietary genomic technologies for the rapid discovery and optimization of novel products from genes and gene pathways. Diversa is directing its integrated portfolio of technologies to the discovery, evolution, and production of commercially valuable molecules with pharmaceutical applications, such as optimized monoclonal antibodies and orally active drugs, as well as enzymes and small molecules with agricultural, chemical, and industrial applications. The company has formed significant joint ventures with international technology leaders including Syngenta (Zymetrics Inc.).

Syngenta (NYSE: SYT) is a world-leading agribusiness. The company ranks first in crop protection, and third in the high-value commercial seeds market. Sales in 2001 were approximately US $6.3 billion. Syngenta employs more than 20,000 people in over 50 countries. The company is committed to sustainable agriculture through innovative research and technology. Syngenta is listed on the Swiss stock exchange and in London, New York and Stockholm.