July 21 (Reuters) - DoValue said that a consortium of the financial company, Bain Capital and Fortress has been chosen by National Bank of Greece (NBG) as the preferred bidder in relation to project frontier for a short period of talks. NBG, Greece’s second-largest lender by assets, is looking to offload a portfolio of soured loans known as project frontier. Earlier on Wednesday, NBG said it was in exclusive talks with the consortium for the sale of non-performing credit. (Reporting by Kanishka Singh in Bengaluru; Editing by Jacqueline Wong)