SUNNYVALE, Calif., December 4, 2000 - United Microelectronics Corporation of Taiwan (NYSE:UMC) filed a lawsuit today against Taiwan-based Silicon Integrated Systems in Federal Court in San Jose, California. In this filing, UMC claims that SiS entered the chip making business by engaging in a systematic pattern of abuse of UMC's intellectual property rights, including patent infringement, misappropriation of trade secrets, breach of confidentiality agreements and unfair competition. UMC's lawsuit seeks a Court order prohibiting SiS from further violations of the law, together with monetary damages in an amount to be determined by a jury at trial.

"UMC intends to protect to the fullest extent of the law the intellectual property that we have spent hundreds of millions of US dollars and countless manhours of engineering and manufacturing effort over the past twenty years to develop," said John Hsuan, UMC Chairman. "We believe that intellectual property is the cornerstone of our success, and know that technological prowess comes only as a result of substantial and independent effort. We cannot sit still while other companies take our people and abuse our proprietary information to launch into the business without making the investments and engineering work required to secure advanced technology legitimately. We do not believe modern industry will tolerate those who seek shortcuts to success through the misuse of intellectual property belonging to others."

"UMC has taken this step only after careful deliberation," explained Mr. Hsuan. "SiS declined our requests for specific assurances that SiS has respected our legal rights, and we saw no other way to protect our shareholders and their property. We trust this is a matter that will be decided in the Courts, and therefore do not expect to comment further on specifics." More detail of UMC's allegations are stated in its Complaint, which is available from the District Court in California and can be viewed here (pdf, 296kb).

Note Concerning Forward-Looking Statements
Some of the statements in the foregoing announcement are forward-looking within the meaning of the U.S. Federal Securities laws, including statements about future outsourcing, wafer capacity, technologies, business relationships and market conditions. Investors are cautioned that actual events and results could differ materially from these statements as a result of a variety of factors, including conditions in the overall semiconductor market and economy; acceptance and demand for products from UMC and technological and development risks.