United Microelectronics Corporation (UMC) experienced a pre-market plunge of 6.24% as the stock faced significant selling pressure during the early trading session.

The decline came amid broad weakness in the semiconductor sector, with multiple chip and storage shares extending declines in overnight trading. This sector-wide downturn contributed to negative market sentiment and dragged down UMC's stock price alongside its peers.

Furthermore, UMC saw concentrated profit-taking from investors following a recent rally, driven by uncertainty over speculative reports regarding a potential partnership with Intel. The company has issued a statement discouraging reliance on market rumors and urging attention to official disclosures, which heightened investor caution and triggered the sell-off.