(Reuters) - Goldman Sachs Group Inc named David Solomon as its next chief executive officer on Tuesday, replacing Lloyd Blankfein who will step down on Sept. 30. Blankfein will step down as chairman at the end of the year and will accept the title of senior chairman after his retirement, the bank said. Reporting By Aparajita Saxena in Bengaluru; Editing by Saumyadeb Chakrabarty