BUZZ-Petra Diamonds: shares hit as co lowers prices
** Petra Diamonds (LSE: PDL.L - news) down at 2.5 mth lows & poised for biggest one-day drop in 6 mths as it lowers its diamond pricing
** Due to the softness in the diamond market, Petra lowered FY guidance for Finsch, Cullinan & Koffiefontein mines
** Co estimates H1 LFL diamond prices were down on avg by 8-9 pct
** In brighter spot, raises FY production guidance to about 3.3 mln carats vs about 3.2 mln carats (RM (LSE: RM.L - news) : tricia.wright1.thomsonreuters.com@reuters.net)