US producer prices slipped slightly in September after August\'s gains, pulled down by falling food prices, leaving wholesale inflation almost flat from a year ago, the Labor Department said Tuesday. Producer prices dropped 0.1 percent from August; excluding volatile food and energy, prices were up 0.1 percent. For the year to September, producer prices -- an indicator of inflationary pressures -- were up a bare 0.3 percent. That was the lowest 12-month change since October 2009, when prices were contracting, providing evidence that economic growth remains tepid. \"Despite noise in components, wholesale inflation is tame,\" said economist Chris Low at FTN Financial.