Geneva, June 23, 2003 - STMicroelectronics (NYSE:STM)
announced that it has been added to the Philadelphia Stock Exchange Semiconductor Sector Index (SOX) effective today. The SOX is a widely followed, price-weighted index comprised of 18 companies that are primarily involved in the design, distribution, manufacturing, and sale of semiconductors. Based on its closing stock price on June 20th, ST should be firmly within the top 50th percentile of the SOX.

Lynn Morgen, Group Vice President - Corporate Development at ST commented, "We are very pleased to have been selected for inclusion in this prestigious Index. We believe this reflects ST's performance track record and the global nature of the semiconductor industry."

In addition to the SOX, ST belongs to a number of high-profile stock indexes. Among these: the CAC-40, a modified capitalization-weighted index of 40 companies listed on the Paris Bourse; The MIB 30, a capitalization-weighted index of 30 top Italian companies traded on the Milan Stock Exchange; the NYSE Composite Index, a market-capitalization-weighted index of the 2045 stocks traded on the New York Stock Exchange; the NYSE TMT Index; the NYSE International 100 Index; the NYSE World Leaders Index; the Dow Jones Euro STOXX Technology Index; the AMEX Semiconductor Index; and numerous other technology indexes administered by international investment banks.

Also effective today, ST has been added to the Dow Jones Technology Titans 30 Index, which is designed to capture the performance of the most important and influential technology companies. Additionally, ST has recently been honored by its inclusion in the Financial Times top 500 global companies and as one of only three semiconductor companies in BusinessWeek's InfoTech 100.

About STMicroelectronics
STMicroelectronics is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. In 2002, the Company's net revenues were $6.32 billion and net earnings were $429.4 million. Further information on ST can be found at http://www.st.com.