International Airlines Group (IAG) announced that traffic rose by 7.7 per cent in August to 5.21m passengers, compared with 4.84m one year earlier.The airline group's traffic measured in Revenue Passenger Kilometres rose 5.0% while capacity measured in Available Seat Kilometres was up 5.6%."Underlying market conditions remain unchanged from guidance given at Quarter Two results. Trading conditions at our London hub remain firm. Performance at Madrid continues to be impacted by weak economic conditions, with short haul traffic particularly affected," IAG explained in a statement.In regards to strategic developments, the filing added that Iberia's new low-cost airline Iberia Express has carried more than one million passengers in its first five months of operations.The performance statistics released by IAG comprises of British Airways (including bmi Mainline, excluding bmibaby) and Iberia (including Iberia Express).Shares were trading 0.21% higher at 140.2p by the close in London.MD