OSLO, March 2 (Reuters) - Birger Vikoeren, currently chief-of-staff at the Norwegian central bank, is among the four applicants for the job of deputy central bank governor, the bank said on Tuesday. If successful, Vikoeren, 59, would have oversight of the country’s $1.3 trillion sovereign wealth fund, the world’s largest. (Reporting by Gwladys Fouche, editing by Nora Buli)