A method and catalyst system for producing aromatic carbonates from aromatic hydroxy compounds is disclosed. In one embodiment, the method includes the step of contacting at least one aromatic hydroxy compound with oxygen and carbon monoxide in the presence of a carbonylation catalyst system having an effective amount of a nickel source as the primary catalyst component in the absence of a Group VIII B metal source. In various alternative embodiments, the carbonylation catalyst system can include at least one inorganic co-catalyst, as well as a halide composition and/or a base.