The Federal Reserve is expected to keep interest rates unchanged on Wednesday and may struggle to convince skeptical investors it can tighten monetary policy before the end of the year in the face of U.S. and global economic headwinds. The world's most powerful central bank hasn't hiked rates in about a decade and markets see virtually no chance it will do so at the end of this week's two-day policy meeting. The Fed is scheduled to announce its rate decision at 2 p.m. ET (1800 GMT). A spate of dismal data on the U.S. and global economies has fueled a public row between Fed Chair Janet Yellen and fellow policymakers, ... (full story)