Credit Suisse has upgraded Atlas Iron (ASX:AGO) to Outperform from Neutral despite disappointing FY13 earnings - The company is experiencing growing pains according to the broker, as FY13 underlying earnings were disappointing at $14m versus the broker's estimate of $49m. Differences in reported figures were lower revenue, higher costs and higher depreciation. Earnings are expected to be negative in FY14, given guidance that depreciation will nearly double as short-life mines end. Nonetheless, the recent decline in the stock price has prompted Credit Suisse to upgrade the rating on the stock to Outperform from Neutral with a target price of $1.00 (current price $0.79). Based on the last closing share price, AGO is currently trading at a price-to-earnings ratio of minus 31.40.