This isnt exactly correct. London Overground Rail Operations Limited is a company owned by MTR (Hong Kong Metro operators) and DB (Germany Railways, also owners by EWS Freigt company in the UK and Chiltern Railways). LOROLs contract is managed by TfL. This is much the same as the operatots of Southern which is operated by GoVia. This company Keolis (broadly party of SNCF) and the British Bus operator Go Ahead. Many rail comapnies are like this. Virgin Trains is 51% Virgin and 49 Stagecoach. Other national rail services are managed by DfT; although others are devolved too - Merseyrail, Scotrail, etc Also because LOROLs network interacts with only a few other services - making planing easier. A fear would exist that if TfL controlled all London area based services. these would squeeze off longer distance services from outside the GLA area - to the detriment of those places and to London. Giving TfL control of these services would mean the Mayor controlling transport deep into sussex - not a pleasant thought for them!! Also it worth remembering that Denmark Hill station is about to get a significant amount of money spent on it to improve access.