JOHANNESBURG (Reuters) - Shares of South Africa's Impala Platinum fell to their lowest level in more than nine years on Tuesday after the company said it expected first-half earnings to fall by more than 20 percent as safety stoppages and strikes hit production. The world's second-largest platinum producer is recovering from a five-month strike that cost it 300,000 ounces in lost output. Implats also temporarily closed part of its largest Zimbabwean mine operated by its Zimplats unit after an underground collapse in July. The company plans to announce details of a strategic review this month following a strike by the Association of Mineworkers and Construction Union at the top platinum producers, which ended in June. Prices for the precious metal used for emissions-capping catalytic converters in automobiles also remain depressed, hovering at five-year lows. Implats shares fell as much as 7.7 percent shortly after the market opened, and by 0715 GMT the stock was down 6.4 percent at 72 rand, the lowest level since 2005.