The present invention relates to a process for producing diaryl carbonates by the reaction of an aromatic hydroxy compound (e.g. phenol) with carbon monoxide and oxygen in the presence of a catalyst, a co-catalyst, a quaternary salt and a base, which is characterised in that the reaction is conducted in a melt comprising the diaryl carbonate and the hydroxy compound on which the carbonate is based, and further diaryl carbonate is optionally added to this reaction mixture before work-up.