Diamond production at BHP Billiton dipped 19 percent to 770,000 carats at the end of the three months ending March 31, 2010, reports say. The low production was attributed to the lower average grade recovery from the company’s Ekati mine in Canada. The company owns 80 percent of the Ekati mine. Volume of ore processed in the said period dropped flat at 1.25 million tonnes, reports add.