Petra Diamonds saw strong revenue growth for the year ending June 30, 2011, despite the fact that diamond production remained relatively flat, the company announced Monday.

Revenue for the year stood at $220.6 million, compared to $163.7 million in 2010. Post-tax profits, however, were down from $70.2 million in 2010 to $59.2 million.

The company produced 1,117,795 carats of rough diamonds over the course of the year (compared to some 1.16 million carats in 2010), attributing the drop-off to the planned halt to production at the main pit of the Williamson mine; difficulty in the initial commissioning of the Kimberley Underground mine; and unusually heavy rainfall in South Africa that caused flooding and affected operations.

Petra reported that its plans to increase its annual diamond production to 4 million carats by the 2014 fiscal year and over 5 million carats by FY 2019 were “on target.” The company assumed control of the Finsch diamond mine, acquired from De Beers, on September 14, and the new asset is expected to boost Petra’s diamond production by more than a million carats per year.

Petra Diamonds CEO Johan Dippenaar said that over the course of the year, Petra had consolidated its position as one of the largest diamond miners in the world. Dippenaar noted that global demand for diamonds continued to rise and said that he was “very positive” about Petra’s future for 2012 and beyond.