Cardiff, Newport and Bristol to commission city region strategy
Cardiff, Newport and Bristol will commission a strategy to identify projects to work on as a city region.
Details of how they plan to work together under the title Great Western Cities were unveiled in February.
The three cities' political leaders have now agreed to commission the strategy which will also set out the case for investment and recommend how the projects should be delivered.
It will be launched later in the year.
It is hoped working together as a city region will boost the economy and help to develop renewable energy.
The cities involved have already formed partnerships to shape transport plans.
The launch report said the three cities were already amongst the most successful in Britain, with a combined economic output of £58bn, but could do better.