Petra, after acquiring three mines from De Beers has noticed its net profits rise for the six months ending 31 December 2007. The three mines were Koffiefontein, Cullinan and the Kimberley, and Petra had signed a contract with De Beers for the Cullinan mine on 22.11.07.%%The net profit for the said period was valued at $8.2 million, over the $9.5 million loss during the same period last year. The value of revenue was $32.1 million, while last year it was $8.2 million in the same six months. Petra has gained leverage with the acquisition of the mines.