The central government would merge two public sector undertakings -Rajasthan State Mineral Development Corporation (RSMDC) Ltd and Rajasthan State Mines and Mineral Ltd (RSMML)-to ensure their economic viability in the era of liberalisation. A public notification for merging RSMDC into RSMML has already been published early this week on which objections have been invited as per legal requirements, an official spokesman said.