"Strengthening the leadership and integration of Government policy and activity will help create the conditions for businesses to grow and create jobs. Structure is only one part of the story, but the current fragmented structures make it harder to achieve the results we need."
Hundreds of public service jobs are expected to be erased in the merger - though Mr Joyce said the jobs of the ministers overseeing the various sectors are safe.
State Services Minister Jonathan Coleman said the new ministry would net Government up to $11 million in savings in the medium term.
Most staff would have a seamless transition into their new roles, he said.
"While obtaining savings is not what is driving this change, there will be efficiency benefits.
"It is envisaged that the current separate agencies will form the initial functional units of the new ministry, which will then be further consolidated over time."