Terms of the deal were not disclosed.
David Musto, president and CEO of Ascensus, will serve as CEO of the combined company, which will operate as Ascensus.
"Ascensus and Newport are both respected leaders in the marketplace and well-known for service excellence, deep expertise, investment independence and purpose-built technology," Mr. Musto said in the news release. "We expect the service platform investment, product expansion and enhanced capabilities our union will deliver to be well-received by our collective clients."
Laura Ramanis, Newport's chief operating officer, has been named Newport's interim CEO, replacing Greg Tschider, who stepped down from the post. Ms. Ramanis will be supported by Kurt J. Laning, executive vice president of non-qualified and insurance solutions, along with the Newport's senior management team, the news release said.
Ms. Ramanis and Mr. Laning will join Ascensus' executive leadership team and remain with the company once the deal closes.
"We look forward to working with Laura Ramanis and her leadership team to unify our organizations in the months ahead and are eager to be operating as one team by next spring," Mr. Musto said in the release.
The transaction is expected to close in the first quarter of 2022, subject to regulatory approvals.
The deal will expand Ascensus' retirement plan and fiduciary consulting services, while giving Newport clients greater access to "tax-advantaged savings solutions across retirement, education and health," the release said.
As a result of the merger, Ascensus' assets under administration will jump to more than $700 billion and its tax-advantaged savings participant base will surpass 15 million people across the U.S., according to Ascensus.
Ascensus currently has more than $404 billion in assets under administration and serves more than 113,800 retirement plans, an Ascensus spokesman said.