Mr Key also emphasised his Government's focus on the national security and intelligence sector and also in housing sectors by restructuring those portfolios.
Former Social Development Minister Ms Bennett jumped four places to no.5 in Mr Key's new Cabinet taking the State Services, Social Housing and Associate Finance portfolios as well as retaining Local Government.
Former Defence Minister Jonathan Coleman becomes Health Minister and picks up the Sport and Recreation portfolio and rises from no. 10 onto the front bench at no.6.
Ms Adams becomes Justice Minister and moves up eight places to no.7, and Mr Bridges is the new Transport Minister and moves up to take the final spot on Mr Keys' front bench at No.9.
Maggie Barry is also on the fast track going straight into Cabinet as Minister for Arts, Culture and Heritage, Minister of Conservation and Minister for Senior Citizens.
Mr Key said he taken the opportunity "to both promote and introduce some new talent into the new executive, taking an opportunity to refresh the responsible ministers to create some new portfolios where I think they're required and to modernise the names and emphasis of some of the existing portfolios."
If there were lessons to be learned from the previous Government "I think it was really a failure to rejuvenate fast enough and actually to promote the next wave of senior ministers".
"So one of the big emphasis you can see today is that we are bringing through a group of ministers that we see as the next wave of senior talent and promoting them to the front bench."
Chris Finlayson remains Treaty Negotiations Minister and Attorney-General, but also becomes Minister in Charge of the NZ Security Intelligence Service and Minister Responsible for the GCSB, "working closely with me in my new role as Minister for National Security and Intelligence," Mr Key said.
Mr Key said that in his new role: "I will continue to be responsible for leading the national security system, including policy settings and the legislative framework.
"Mr Finlayson will operate within the framework I set and exercise ministerial oversight of the NZSIS and GCSB, including approval of warrants."
Mr Key said the shake-up was prompted by the growing significance of the portfolios.
"The world has become a more uncertain place."
He would give a formal speech in about a month's time about the risks and the
Government's concerns about current laws around foreign fighters.
Mr Key said he would seek bipartisan support for Labour to pass new Security Intelligence Service (SIS) legislation once Labour had appointed its new leader.
Hekia Parata retains her Education portfolio but is demoted from number seven to no. 10, just outside the front bench.
Craig Foss loses his place in Cabinet, falling four places to no.21.
Mr Key said Mr Foss was a good minister, "but sometimes you just have to make calls about who you're going to have in your top 20."
Mr Key said housing would continue to be "a key area of focus for his Government" with a ministerial team of Bill English, Paula Bennett and Nick Smith assembled to lead that work. "Mr English will have direct responsibility for Housing New Zealand; Ms Bennett will focus on social housing, while Dr Smith will work on housing affordability and construction issues.
The Social Housing portfolio will have responsibility for the government's social housing functions, and for its relationship with the social housing sector."
Other changes include:
• Gerry Brownlee becomes Minister of Defence, while retaining the role of Leader of the House and his Canterbury Earthquake Recovery and EQC portfolios.
• Anne Tolley becomes Minister for Social Development.
• Dr Nick Smith becomes Minister for the Environment.
• Nikki Kaye becomes Minister for ACC.
• Michael Woodhouse becomes Minister of Police. He also becomes Minister for Workplace Relations and Safety - a new portfolio title to reflect the modern focus of what had previously been the Labour portfolio.
• Jo Goodhew becomes Minister for Food Safety.
• Louise Upston and Paul Goldsmith will be Ministers outside Cabinet holding a variety of portfolios.
Two ministers previously outside the top 20 were promoted to Cabinet. Todd McClay will be Minister of Revenue and Minister for State Owned Enterprises, while Peseta Sam Lotu-Iiga will be Minister of Corrections, Minister for Ethnic Communities and Minister for Pacific Peoples.
Chester Borrows loses his Courts portfolio but will be National's nominee for Deputy Speaker which Mr Key said was "a logical step".
"We think he is well respected across Parliament."
A number of Ministers continue largely in their current portfolios including Steven Joyce in Economic Development, Murray McCully in Foreign Affairs, Nathan Guy in Primary Industries, Tim Groser in Trade and Climate Change, and Nicky Wagner in Customs.
Acting Labour Leader David Parker said Mr Key was "trying to rid himself of the responsibilities every Prime Minister has to bear" by handing parts of his intelligence and security duties to Mr Finlayson.
"This is a dereliction of duty. Managing our spy agencies is an integral part of being Prime Minister.
"Oversight of the SIS and GCSB has traditionally been the responsibility of Prime Ministers. It is an unprecedented move to delegate those responsibilities to a lower minister."
Recent controversies in the intelligence portfolios including Mr Key's appointment of his old school friend Ian Fletcher to lead the GCSB, the potentially illegal spying on 88 New Zealanders fingered by the Kitteridge report and the "ramming through" of GCSB legislation made it "apparent that the Prime Minister has not properly exercised his oversight".
"The answer is to do the job properly not palm it off elsewhere," Mr Parker said.
