A near-infrared (NIR), advanced control system has been controlling the gasoline blender at BP France's Lavera refinery for more than 2 years. The blender produces 1 million metric tons/year gasoline (about 21,000 b/d) using multivariable blend-control software in a closed-loop mode. BP's system uses a centralized NIR spectrometer fitted with optical fibers that carry NIR radiation between the instrument and process streams. The analyzer monitors the product stream from the blender and transmits data to the control software, which adjusts the component flow rates to meet target specifications. The system computes blending indices using an innovative approach based on the NIR response of the individual basestocks. The paper discusses NIR analysis, blending optimization, the Lavera project, BP methodology, data treatment, system assessment, and benefits.