A transformation services framework agreement, worth up to £3.5 billion in total and including IT, is being offered to police forces across the England and Wales.
A tender exercise is currently underway, being led by West Midlands Police and Surrey Police, for three to five suppliers on a seven year framework.
The news comes only days after Essex Police launched its own £400 million framework agreement with Northgate Information Services for a crime, intelligence and defendant management system for several local police authorities.
The West Midlands Police tender notice calls for suppliers of IT management, performance and risk management, incident and investigation management, customer and supplier management, and police data and forensics management.
The aim is to deliver a "cutting edge" but cost effective approach to policing, according to a tender notice.
The authorities said that by working together, the benefits would be "improved experience of policing services by end users, realisation of cost savings from transformation initiatives, more efficient delivery of policing services, improved access by forces and others to private sector capability, and a more innovative and cutting edge approach to 21st century policing".
The two lead forces expect to spend up to £1.5 billion if only they take the framework agreement, but up to £3.5 billion if other forces across the country sign up.
"While the forces have a high degree of commonality in their requirements, they also wish to cater for specific requirements in their local areas," they said. "To allow for this the forces envisage having separate service contracts with the successful providers or with a joint venture entity."
Work is expected to begin in February 2013. Suppliers have until 4 April this year to express their interest.