Rio Tinto's diamond unit in Zimbabwe has begun work on a $300m expansion programme to raise output six-fold.
The company has begun preparatory work for the planned expansion in a 300,000-carat-per-year diamond mine, Murowa, in southern Zimbabwe.
The shareholders of Murowa earlier commissioned a review of expansion feasibility studies, to be completed by the end of 2010 in the wake of an improved climate of investment in the country.
Rio Tinto head of Murowa Neils Kristensen said the expansion will increase production by six to seven times and double jobs, according to Reuters.
The expansion will increase the capacity of the mine to 1.8 million carats a year of high-quality gem production.
The company is also in talks with the government on the recent ban of diamond sales from the country, Kristensen said.