(ICIS) -- Prices of styrene butadiene rubber (SBR) in India are set to weaken further in the fourth quarter as feedstock butadiene (BD) prices tumble and car sales fall, industry sources said on Tuesday. Prices of non-oil grade 1502 SBR have plummeted by $700/tonne (┬511/tonne) since mid-September to $3,400-3,500/tonne CFR (cost & freight) India in the week ended 12 October, ICIS data showed. This is in line with the more than a $800/tonne drop in feedstock BD prices to $2,300-2,400/tonne CFR NE (northeast) Asia during the same period. Market players expect prices of SBR 1502 to fall further to around the $3,000/tonne level.