About 60 jobs are expected to be cut in a merger between the Ministry of Fisheries and Ministry of Agriculture and Forestry announced today.

State Services minister Tony Ryall said the merger would deliver better results by reducing "back-office bureaucracy".

It was expected to net a $10 million annual saving in the first full year, with $8.5 million annual savings over time, when it took effect on February 1, 2012, he said.

A spokeswoman for Mr Ryall said most of those who lose their jobs are expected to be back-office staff from the Wellington headquarters of the merged ministries.

Roughly 2300 people work across both ministries.

Exact details of the cuts would be decided in the next year, she said. "But I imagine they will be duplicated roles."

Wayne McNee, current MAF chief executive and a former Fisheries CEO, will be acting chief executive of the newly merged ministries.

The Ministry of Agriculture and Forestry and the Ministry of Fisheries were first split in 1995 by the Jim Bolger-led National administration. Today's merger announcement reverses that decision.

The Public Service Association has called the move an unnecessary distraction for its members in a time of national emergency.

Its national secretary Richard Wagstaff said claims the merger would save $10 million annually were guesswork and a smokescreen for a small-government agenda.

"We've been on this merry-go-round before when the Ministry of Agriculture and Fisheries was carved up in 1995. Dozens of workers lost their jobs and services were contracted out. That restructuring was meant to provide a more efficient service and save money. Now we are told the opposite is true."

Mr Wagstaff said the cost of restructuring the two ministries could outweigh any efficiency gains.

He understood 64 jobs would be lost, but did not know which departments they would be cut from.

Hundreds of staff were now anxiously awaiting a decision on whether they would be made redundant, he said.

"They're anxious about whether that axe will fall on them. They've got a lot on their plate at the moment - it's tough.

"The Government is leading the charge on job cuts in the recession."

Mr Ryall said the cost of the merger would be covered from within "existing baselines".

It would lower the cost of delivering public services in difficult economic times, he said.

"This merger is part of the Government's ongoing programme to improve public services during times of increasing financial restraint and rising public expectation of service delivery.

"It will reduce duplicated and overlapping functions between the two organisations - and it will create an agency with better abilities to give support to primary industries."

The move follows the Ministry of Agriculture and Forestry being merged with the New Zealand Food Safety Authority in July 2010.

Agriculture and Forestry Minister David Carter said the merger would create a single voice for New Zealand's primary industries.

The new agency would be better equipped to deal with iwi, local Government and international trading partners on regulatory, food and biosecurity issues, he said.

"New Zealand's future prosperity relies on the strength and productivity of our primary industries."

Fisheries minister Phil Heatley commended the work of his staff in the Ministry of Fisheries.

He said they had promoted an internationally competitive fisheries industry, he said.