'Transforming Rail Travel' is a deal between the two organisations to continue a two-year arrangement with the aim of delivering further enhancements to services and facilities.
Measures include a pilot smart-ticketing scheme, more CCTV cameras at stations, more park and ride provision and better ticket vending machines.
The original partnership agreement was signed in September 2011.
Councillor John McNicholas, the chairman of Centro, said: "Two years on the aspirations of the original partnership agreement have been substantially delivered.
"The time is now right for a new agreement to set out the way forward for the next two years.
"We are delighted to be signing a new agreement that will see us work together to continue to create a more user friendly, accessible railway and contribute to greater standards of personal mobility."
Patrick Verwer, London Midland managing director, added: "We are committed to improving services for our passengers and this agreement between London Midland and Centro demonstrates a shared aspiration to improve public transport across the West Midlands region.
"Working together to align rail, bus and Metro services is just one of the major benefits of having an integrated transport authority."