Cordero, Camden County Freeholder Director Louis Cappelli Jr., and Camden Mayor Dana L. Redd described the plan Thursday to the Inquirer Editorial Board.
Other New Jersey counties have explored police regionalization, but Camden County's move is unprecedented in the state.
Cappelli said that the figures were rough estimates, but that the state had agreed in principle to bear the start-up costs. A spokeswoman for the Department of Community Affairs said no final determination had been made on what, if anything, the state would contribute.
The projected savings in the police budget would come from eliminating the extras in police contracts, such as percentage bumps for working various shifts and additional pay for experience, Cappelli said. The savings would allow the county to hire up to 400 new officers along with 100 civilian employees - far more than make up the current force, which numbers 270.
Officials said the new force would cost about the same as the present Camden Police Department. The city police budget for the last fiscal year, which ended June 30, was nearly $60 million.
Cordero said officers' salaries would generally stay the same.
No officer "will make less in terms of base pay than they are making now," said Cordero, principal of the Cordero Group. His Lyndhurst, N.J., law-enforcement consulting and police-technology firm will be paid about $20,000 a month for about a year to help build the force.
At this point, the planned county force is envisaged to have only a metro division to patrol Camden City.
Suburban towns have resisted joining the force. It is staunchly opposed by Camden police unions, which characterize it as a union-busting move that will not make the city safer or save money.
City Councilman Brian Coleman, a vocal opponent of the regional police force, said he had yet to see the cost projections.
"I don't think it will solve anything. . . . I think we have a deployment issue," said Coleman, who has said he thinks officers are excessively used to provide security at waterfront events.
The Camden department is about 100 officers smaller than it was in January 2011, when nearly half the department was laid off as the city faced a $26 million budget deficit. While many of the fired officers were rehired, many others have retired or otherwise left the force.
John Williamson, president of the Fraternal Order of Police lodge in Camden, said officials of the union were reviewing their options with lawyers.
Backers of the planned regional force say there is urgency to increase the police presence in the city. Camden has recorded 43 homicides so far this year and is likely to exceed last year's total of 49. The record is 58 homicides in 1995.
"We have got to make to this city safe and I'm willing to take this step for the future of Camden," Redd said.
At a news conference Wednesday, Redd said a number of city residents were in favor of the force. She introduced a newly created community congress of residents who endorsed the plan.
Sheila Davis, president of Lanning Square West Residents in Action, said it "would be an obstruction of justice" if residents did not support the new force.
Officials hope to start hiring new officers by October and dispatch batches of the new hires on walking patrols in crime hot spots as they draw down the current force.
"At no time will Camden be left without police officers," Redd said. "We want to dispel that rumor."
The county force will be governed by a shared-services agreement between the city and county that Cappelli said was expected to be finalized by October.
Even if the state provides the start-up costs, it would be a challenge for the financially strapped city to sustain the continuing cost of a 400-member force.
Gov. Christie has asked Camden to start weaning itself from state aid and has been slowly cutting the amount the state provides. City officials said Camden will receive $105 million in state aid, or 70 percent of its $150 million budget for the 2012-13 fiscal year, which began July 1. State aid the previous year was $108 million.
Redd said Thursday she was confident the state would provide enough aid each year to sustain the metro division, noting that Trenton has pushed for the regional force.
On Wednesday, in an effort to expedite the hiring process, the county submitted a request to the state Civil Service Commission for a waiver from rules governing hiring and promotions.
Cappelli said officials hope to get an answer by October. The hiring, he said, would coincide with layoff notices to the current city force.
Camden officers for several years have worked without a contract, though the terms of the last contract still apply. Only up to 49 percent of them would be hired for the new force, according to officials, so it would not be bound by the old contract.
About 1,900 applicants, including 90 current Camden officers and 60 officers from other departments in Camden County, have expressed interest in joining the new department, Cappelli said.
Preparations for the new force appear to be well along. Cordero said the new uniforms would be dark blue, with smaller patches and larger badges, and the new cars would remain black and white but with a county metro division logo.
The projected savings include $3 million to $4 million from eliminating shift differentials; $1.2 million to $2.5 million from eliminating holiday pay; and the same amount from ending differentials for service longevity.
Williamson said the union had been responsive to some of the city's demands for concessions.
"We already agreed to that," he said of relinquishing a shift differential and capping longevity, citing meetings in June and July with City Attorney Marc Riondino and Finance Director Glynn Jones.
But city spokesman Robert Corrales said that agreement was never put in writing.
"While they claim they want to negotiate, they have yet to submit any official written concessions," Corrales said in an e-mail.
Contact Darran Simon at 856-779-3829 or dsimon@phillynews, or follow on Twitter @darransimon.