Credit Suisse has kept its 'outperform' rating and 4,000p target price for mining giant Rio Tinto following a revised technical report for the Oyu Tolgoi copper and gold project in Mongolia which included higher costs."A capex increase has been well anticipated by the market in our view and reflected, along with lower iron ore, in Rio's current share price. The potential scope changes are consistent with Rio's (and sector), new paradigm to lower capex and development risks, something the market should welcome."UBS has reduced its target price for insurance group Aviva from 450p to 440p following this month's 2012 results but has maintained its 'buy' recommendation for the stock.While dividend forecasts have been cut, the broker said that its debt reduction targets can be funded from organic capital generation alone. An acceleration of repayments in the second half "would both reduce financial risk and quash any residual concerns over equity issuance".Panmure Gordon has maintained a 'hold' rating for travel leisure firm TUI Travel, saying that while the first half was strong, shares are fully valued.The stock is trading at 11.1 times estimated 2013 earnings, in line with the market. Historically, the broker said that tour operator usually trade between a 25% discount and in line with the market and normally underperform over the April to September period.BC