Guardian Media Group has confirmed that it is set to hire a financial adviser to carry out a strategic review of its assets. The review could end with the profitable Trader Media division being sold off, whether wholly or partially. Trader Media publishe Auto Trader and Bike Trader. Radio, regional newspaper and classifieds assets could be looked at. GMG bought 52% of the business, to add to its existing 48% stake, for almost £600m three years ago. A sale could net more than £1 billion.