SYDNEY, Aug 12 (Reuters) - Australian shares are likely to start lower on Wednesday as China's shock currency devaluation added to worries about global growth and dented risk sentiment. Australia's share price index futures eased 0.5 percent to 5,378, a 95.2-point discount to the close of the underlying S&P/ASX200 index on Tuesday. The benchmark dropped 0.7 percent in the previous session. A raft of earnings are due to be released, including from Commonwealth Bank of Australia, AGL, CSL
