By Dan Molinksi

Chevron Corp. reported a shutdown related to a gasoline-making fluid catalytic cracking unit at its Pasadena, Texas refinery late Monday.

The refinery's statement to the Texas Commission on Environmental Quality said the incident happened Sunday and resulted in emissions of carbon monoxide, sulfur dioxide and other gases that lasted more than three hours.

The shutdown at the 110,000-barrel-a-day Houston-area refinery comes less than a month after the refinery performed FCCU-related maintenance.

Write to Dan Molinski at dan.molinski@wsj.com