WASHINGTON, Aug 11 (Reuters) - The U.S. Federal Reserve should announce its timeline for beginning to reduce its massive bondholding next month and start tapering them in October, Dallas Federal Reserve President Robert Kaplan said on Wednesday. “It would be my view that if the economy unfolds the way I expect. ... I would be in favor or announcing a plan at the September meeting and beginning tapering in October,” Kaplan said in an interview with CNBC. He repeated doing so would give the Fed more flexibility to be “patient” on raising interest rates. (Reporting by Lindsay Dunsmuir; Editing by Jonathan Oatis) Our Standards: The Thomson Reuters Trust Principles.