A process for the preparation of oxalate esters by the catalytic oxidative carbonylation of an amide acetal having the formula ##STR1## with carbon monoxide and oxygen or oxygen-containing gas in the presence of a metal salt catalyst, an amine base and a catalytic amount of an alcohol. Preferably a catalytic amount of particular oxidizing metal salts is employed along with a catalytic amount of an amine salt compound which may be formed in situ by the addition of an acid. Alternatively various counterions and ligands of the metal salt catalyst may be employed.