Mining giant BHP Billiton's revenue from diamonds totaled $1.517 billion in the financial year ending June 30, 2011, an increase of 19.3% compared to FY 2010.

The rise in revenue was attributable to strong worldwide demand and a shortage of rough diamonds and came despite the drop-off in production at BHP Billiton's Ekati mine in Canada. Ekati produced 2.5 million carats in the period reported, an 18% drop year-on-year.

The company expects lower average ore grades to continue affecting Ekati's diamond production in the near future.