Tainan, Taiwan, May 24, 2012 - United Microelectronics Corporation (NYSE: UMC; TSE: 2303) ("UMC"), a leading global semiconductor foundry, today held a groundbreaking ceremony for its 300mm Fab 12A Phase 5 & 6 (P5 & P6) at its Tainan, Taiwan fab complex. The expansion begins UMC's new generation of 300mm manufacturing that will extend 28nm production and establish a solid foundation for 20nm and beyond to meet customers' high-end demand, thus ushering in the company's next era of growth.

Stan Hung, Chairman of UMC, said, "UMC remains optimistic about the long-term outlook of the semiconductor and foundry industries. However, with increasing industry volatility, a clearly defined business strategy is needed in order to take full advantage of upcoming market opportunities. We stay firm to our 'Customer-Driven Foundry Solutions' approach that is constituted on the classical foundry model and open ecosystem approach. This commitment enables true synergies between UMC, customers, and ecosystem partners. Based on this philosophy, we will continue to invest timely capex according to our key position in the supply chain so that customers, partners and UMC may prosper together. Cumulative capex for UMC's Fab 12A phases 1-4 is projected to reach US$ 8 billion, with P5 & P6 to add nearly US$ 8 billion more. There are further plans for P7 & P8. This balanced capacity expansion demonstrates UMC's determination to maintain self-sustainable growth."

Dr. Shih-Wei Sun, CEO of UMC, said, "This past decade, UMC's 300mm fabs in Taiwan and Singapore helped UMC strengthen our position as a first-tier foundry provider. Our internal R&D efforts continue to prove successful with the development of progressive advanced technologies. 28nm Poly SiON is now ramping mobile communication and computing products, 28nm Gate-Last HK/MG is set to start pilot production of flagship products in 2H this year, and 20nm HK-Last HK/MG and 14nm FinFET are advancing smoothly. UMC also cooperates closely with customers on 300mm specialty technologies such as HV, embedded non-volatile memory, BSI CMOS image sensor, 2.5D interposer, and 3D IC TSV to provide a truly comprehensive, leading foundry technology platform. We believe that supply chain collaboration will become increasingly important to address dynamic market requirements while minimizing risk. The P5-P8 fab complex will be characterized by close partnerships with customers and vendors to align with their technology roadmaps, enabling customers to introduce their future products while propelling UMC growth. Going forward, UMC's 'customer-driven foundry solution' approach will ensure UMC's sustained competitiveness, profitability, and ROE improvement for years to come."

UMC has operated in the Tainan Science Park since November 1999, when Fab 12A was established as Taiwan's first 300mm fab. The state-of-the-art P5 & P6 will provide advanced 28nm, 20nm, and 14nm capacity, and is scheduled for equipment move-in during the second half of 2013. Total cleanroom area is 53,000^m2, about the size of 10 American football fields. P5 & P6 are planned to create 2,600 jobs and to contribute 50K wafers per month, bringing total monthly design capacity for Fab 12A to 130K wafers. With the planned P7 & P8, the eight phase fab complex will have a total design capacity of 180K wafers per month. UMC continues to expand in the Tainan Science Park to fulfill its commitment to "invest in Taiwan as a base for establishing a global presence."

UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that provides advanced technology and manufacturing services for applications spanning every major sector of the IC industry. UMC's customer-driven foundry solutions allow chip designers to leverage the strength of the company's leading-edge processes, which include production proven 65nm, 45/40nm, mixed signal/RFCMOS, and a wide range of specialty technologies. Production is supported through 10 wafer manufacturing facilities that include two advanced 300mm fabs; Fab 12A in Taiwan and Singapore-based Fab 12i are both in volume production for a variety of customer products. The company employs approximately 14,000 people worldwide and has offices in Taiwan, Japan, Singapore, Europe, and the United States. UMC can be found on the web at http://www.umc.com.

Note From UMC 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. Further information concerning these risks is included in UMC's filings with the U.S. SEC, including on Form F-1, F-3, F-6 and 20-F, each as amended.