Catalytic cracking process

In a catalytic process for cracking a hydrocarbon charge comprising subjecting a hydrocarbon charge to cracking conditions in the presence of a catalyst, the improvement wherein the catalyst contains by weight:

• (a) about 50 to 95% of a matrix selected from the group consisting of at least one of alumina, clay, silica, silica-alumina, alumina-boron oxide, magnesia, silica-magnesia, zirconia and titanium oxide, and characterized by the following textural properties:
• TPV (Total Pore Volume).gtoreq.0.4 cm.sup.3 /g
• S (Specific Surface).gtoreq.100 m.sup.2 /g
• PV.sub.75 (Volume of pores with diameter greater than 7.5 nm).gtoreq.0.25 cm.sup.3 /g
• PV.sub.75 /TPV .gtoreq.0.5
• (b) about 5 to 50% of a zeolite characterized by:
• a SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio from about 8 to 70,
• a sodium content lower than 0.15% by weight, determined on a zeolite roasted at 1100.degree. C.,
• a parameter a of unit cell size ranging from 24.55.times.10.sup.-10 m to 24.24.times.10.sup.-10 m,
• a sodium ion uptake capacity, expressed in grams of sodium per 100 grams of neutralized and roasted zeolite, higher than about 0.85,
• a specific surface higher than about 400 m.sup.2 /g,
• a steam adsorption capacity at 25.degree. C. (at a ratio between the water partial pressure and the saturation vapor pressure of water at 25.degree. C. P/P.sub.o of 0.10) higher than 6% by weight,
• a pore distribution such that from 1 to 20% of the pore volume is pores of diameter ranging from 20 to 80.times.10.sup.-10 m, the remaining pore volume being essentially pores of diameter lower than 20.times.10.sup.-10 m.