Hydrocarbon upgrading process

A process of upgrading a sulfur-containing feed fraction boiling in the gasoline boiling range which comprises:

• hydrodesulfurizing a catalytically cracked, olefinic, sulfur-containing gasoline feed having a sulfur content of at least 50 ppmw, an olefin content of at least 5 percent and a 95 percent point of at least 325.degree. F. with a hydrodesulfurization catalyst in a hydrodesulfurization zone, operating under a combination of elevated temperature, elevated pressure and an atmosphere comprising hydrogen, to produce an intermediate product comprising a normally liquid fraction which has a reduced sulfur content and a reduced octane number as compared to the feed;
• contacting at least the gasoline boiling range portion of the intermediate product in a second reaction zone with a catalyst of acidic functionality comprising a zeolite having a reduced surface acidity, said zeolite having been contacted with dicarboxylic acid to effect a reduction in surface acidity without a substantial reduction in overall acid activity, to convert it to a product comprising a fraction boiling in the gasoline boiling range having a higher octane number than the gasoline boiling range fraction of the intermediate product.