Diversified miner African Rainbow Minerals (ARM) expects its headline earnings a share for the six months ended December 31, to increase by between 8% and 15% to between R11 and R11.80, compared with the R10.23 reported for the first half of the prior financial year. This positive impact is as a result of an increase in the average realised dollars prices for most of the commodities that ARM produces, as well as a weaker average rand/dollar exchange rate.