HARRISBURG — Wolf administration officials said Monday that their plan to consolidate four state agencies into a single department overseeing health and human services programs will likely lead only to "minimal" layoffs and will not result in program cuts.

In their first public statements on the plan, officials said the proposed merger of the Departments of Aging, Health, Drug and Alcohol Programs, and Human Services would save money and result in more efficient delivery of services. But they declined to estimate the size of the savings or the number of jobs that might be lost.

Administration officials promised more details next week, when Wolf delivers his state budget proposal, in which he will have to address a shortfall projected to reach nearly $3 billion over this year and next.

News of the merger leaked out late Friday in an email the administration sent to potentially affected state workers. Together, the four departments have more than 18,000 employees, although the vast majority work in Human Services.

"Over the past several months," Gov. Wolf said in a statement, "I have worked closely with these four departments to break down silos and reimagine how we deliver critical services that will provide treatment to those suffering from substance use disorder, ensure children are receiving high-quality services, and expand community-based opportunities for seniors."

Several social-service advocates on Monday said they were generally supportive of the proposal, and believed it could result in more efficient and holistic policies and services.

"In a difficult funding environment, it is far better to try something like this than to cut services," said Sue Walther, executive director of the Mental Health Association in Pennsylvania.

Legislative leaders, whose members would have to approve combining state agencies, also signaled interest in at least considering the plan.

"Working through budget hearings, we expect to hear from the Wolf administration how these departments will provide these valuable services while maintaining the level of assistance for these delicate constituencies," Senate Majority Leader Jake Corman (R., Centre) said in a statement.

The announcement comes as the administration in recent weeks has announced cost-cutting measures in other areas across state government. But a spokesman for Wolf said Monday that the primary goal of creating a Department of Health and Human Services would be to improve services.

Of the agencies targeted, the Department of Human Services has more than 17,000 workers. The Department of Health has more than 1,200, while the Department of Aging has 93 and the Department of Drug and Alcohol Programs has 69, according to administration tallies this month.

Each has its own cabinet-level secretary position. The secretary of the Department of Drug and Alcohol Programs, Gary Tennis, left his agency last week, telling reporters he was fired for opposing the merger plan. Under the governor's plan, the cabinet would retain a representative of the state's efforts to address drug problems, as well as the secretary of the new department.

In a conference call with reporters, Wolf's secretary of policy and planning, Sarah Galbally,  said the administration wants to have legislation creating the new department passed by the end of June.

"Creating a new unified Department of Health and Human Services dramatically improves our ability to deliver services while reducing costs to taxpayers," she said.

Tom Herman, president of SEIU Local 668, said the union does not necessarily oppose consolidation, but wants to make sure there is little to no impact on its members.

"Many of these agencies serve the same clients, and the inability for one agency to share data with another agency has been a problem at providing efficient service in the past," he said.

In Allegheny County, for instance, the Department of Human Services already houses aging and drug and alcohol services. The county's Health Department is separate. Allegheny County made an effort to better integrate human services about 20 years ago, said director Marc Cherna.

"We were able to make tremendous inroads in terms of helping people, because many of the people we serve are in more than one system," Cherna said, adding that there were budgetary savings as well. "It's a more efficient and better way to provide services and to operate. I'm very pleased that they are doing this."

Joan Benso, CEO of Pennsylvania Partnerships for Children, said the proposed consolidations could make some services more coordinated. She cited the Women, Infants and Children (WIC) program. It provides nutrition education and food assistance to pregnant women and young children and is run out of the Health Department, while other nutrition assistance programs are run by the Human Services Department.

"The way we see this is a more streamlined and integrated way to deliver services," Benso said.

Laura Princiotta, CEO of the Arc of Philadelphia, which serves and advocates for people with intellectual and developmental disabilities, said she did not hear of the consolidation until Monday afternoon. From her standpoint, there has not been a problem with state department overlap, as the Arc's state funding comes from only one department, but she thought the merger could be beneficial.

"As far as I can tell right now," she said, "consolidation is good. Having silos at that level of government isn't necessarily a good thing. If it results in efficiency and better access to services for people, then I think it would be a good thing."

Kate Giammarise of the Pittsburgh Post-Gazette and staff writer Stacey Burling  contributed to this article.