October NY world sugar #11 (SBV25) on Thursday closed down -0.16 (-1.03%), and December London ICE white sugar #5 (SWZ25) closed down -4.50 (-0.98%). Sugar prices extended Wednesday's selloff on Thursday, with NY sugar slumping to a 4.25-year nearest-futures low and London sugar sliding to a 4-year low.   Ramped-up sugar production in Brazil is boosting supplies and undercutting prices.  Unica reported Wednesday that Brazil's Center-South sugar output in the second half of August rose by +18% y/y to 3.872 ...