British factory costs fell in June at their sharpest annual rate since 1997 and output prices dropped at their fastest in 7-1/2 years, suggesting inflation will fall sharply in the coming months. The Office for National Statistics said on Friday output prices, goods leaving the factory gate, fell 1.2 percent year-on-year, the sharpest drop since December 2001 and more than the 0.8 percent fall expected by analysts. Input prices fell 11 percent on the year, less than forecasts for a 12.2 percent decline but still the weakest annual rate since April 1997. But crude oil prices jumped 14.3 percent in June alone, the biggest monthly rise since January 2005.