A process is described for maximization of light olefins, preferably ethylene, by the catalytic cracking of feeds of saturated hydrocarbons, with molecular size in the range from 4 to 6 carbon atoms. The process uses a catalyst based on a zeolite of type ZSM-5 with low sodium content and modified with nickel, with concentration by weight of nickel, expressed in the form of oxide, in the range from 0.1% to 20% relative to the weight of zeolite in the catalyst, and operating conditions that involve a temperature between 400° C. and 650° C. and feed partial pressure between 0.1 and 1.0 MPa, so that the product recovered is rich in light olefins, with ethylene/propylene ratio in the range from 0.25 to 2.00.