MADRID, Oct 28 (Reuters) - Merger negotiations between Spanish lenders Unicaja and Liberbank to create the country’s fifth biggest lender in terms of total assets are still ongoing, Unicaja’s chairman Manuel Azuaga said in a statement on Wednesday. The chairman also said that due diligence was still being carried out and no agreement had been reached as of yet since the lenders hired advisers earlier this month. (Reporting by Jesús Aguado; additional reporting by Emma Pinedo; editing by Ingrid Melander)