ROME, Nov 20 (Reuters) - The Argentine government will introduce the European prospectus for its $20 billion debt swap in Luxembourg, probably in January, a source close to the dossier told Reuters.

Under EU regulations, Argentina could present its prospectus at a European level in Luxembourg, and it would only subsequently go to regulators in Italy -- where the majority of small bondholders live -- for verification, the source said. (Reporting by Stefano Bernabei)