London - Petra Diamonds Ltd said on Monday it expected full-year results below analysts' average forecast, citing softness in the diamond market.
Shares in the company, which has four producing mines in South Africa and one in Tanzania, fell up to 9 percent on the London Stock Exchange.
The miner revised its full-year production guidance to about 3.3 million carats from about 3.2 million carats.
Analysts on average had expected full-year pretax profit at $188.84 million, on revenue of $532.01 million, according to Thomson Reuters I/B/E/S.
Due to the softness in the diamond market, Petra lowered its full-year guidance for the Finsch, Cullinan and Koffiefontein mines.
It estimates that diamond prices on a like-for-like basis were down on average by 8 to 9 percent in the first half ended December 31.
Petra reported a 16 percent jump in first-half revenue to$214.8 million, helped by sales proceeds for two exceptional diamonds for combined revenue of $38.7 million.
The company said it would pay a maiden dividend of 2 pence per share for the 2015 financial year.
Shares in the miner were down 8 percent at 166.10 pence at 08h06 GMT.
Reuters