(IDEX Online) - De Beers has reportedly cut the price of larger rough by as much as 20 per cent at this week's sight (cycle 6) in Gaborone, Botswana, amid increasing caution from buyers. The move follows price reductions last month and a drop in total sales of almost a third during cycle 5, down to $450m.Prices of stones over 2-cts have been reduced by 10 to 20 per cent, according to a Times of India report today, although smaller stones have not been affected, it said.The discounts create a big headache for manufacturers holding stock bought at higher prices, according to Dinesh Navadiya, chairman of the Indian Diamond Institute."They will now be forced to sell the polished diamonds at the currently reduced prices," he said. "They had purchased the rough at a higher price a few months ago."Many factories in Surat are already working reduced hours because of slow demand and tight margins.De Beers does not comment on price information.