Credit Suisse has reiterated its 'outperform' rating and 4,000p target price for mining giant Rio Tinto, following yesterday's announcement of a CEO change and non-cash impairment charge 14bn dollars."After the market digests this news we think the focus should remain on iron ore prices, project delivery and the larger macro picture, all which remains unchanged following [the] announcement especially given current head of iron ore (80% of earnings/65% NPV) takes over as CEO, share price pressure should be seen as buying opportunity."Aerospace components engineer Meggitt was a high riser on the FTSE 100 on Friday morning after Barclays Capital upgraded its rating for the stock from 'equal weight' to 'overweight' and raised its target price from 450p to 520p. BarCap said that the shares' 20% valuation discount to peers "will close as investors in the aerospace cycle look away from the more expensive pure-play names with original equipment or aftermarket exposure, and seek sector laggards like Meggitt."Nomura has upgraded its rating for oil and gas group Ophir Energy by two notches, from 'reduce' to 'buy', saying that highly-geared exploration and appraisal (E&A) drilling in 2013 could be a 'company maker'.The broker said that Ophir has a leading exposure to pure exploration. "In a 'blue-sky' success scenario, 2013 drilling could be worth $17bn or c.500% of the current share price, the highest in our coverage universe."BC