Olefin production

A process to stabilize an olefin production catalyst system comprising wherein said catalyst system comprises a chromium compound, a pyrrole-containing compound and a metal alkyl, wherein said process comprises the steps of:

• reacting the three catalyst system components in the presence of an unsaturated hydrocarbon;
• and
• contacting and stabilizing said catalyst system with a mononuclear aromatic compound selected from the group consisting of toluene, benzene, xylene, mesitylene, hexamethylbenzene, n-butylbenzene, and mixtures thereof;
• wherein said catalyst system and mononuclear aromatic compound are contacted prior to contacting the catalyst system with a reactant at a temperature within a range of about -50.degree. to about 70.degree. C., for a time of less than 1 hour, and under a dry, inert atmosphere.