One of Carroll's sunbelt multifamily properties. Photo courtesy of RMR Group

Newton-based RMR Group is expanding its multifamily holdings with an $80 million acquisition that gives it a portfolio of 28,000 apartments concentrated in Sunbelt markets.

The firm announced its acquisition of Atlanta-based MCP Partnership Holdings, which owns the Carroll platform of 81 apartment properties.

Carroll operates over 90 percent of the properties under the Arium Living brand. The firm’s holdings are located in eight states and include major concentrations in metros such as Atlanta, Orlando, Fort Lauderdale, Tampa and Raleigh-Durham.

The acquisition would expand RMR Group’s assets under management by $7 billion to $44 billion. Currently, RMR Group owns approximately 2,100 properties in various commercial real estate categories.

RMR Group said it expects the acquisition to increase its recurring revenues by more than $35 million, and deliver up to $13 million in additional adjusted EBITDA on an annual basis.

The transaction is expected to close this fall.

In 2022, the company notified elected officials of its potential interest in redeveloping its properties at the corner of Causeway and North Washington Streets in Boston’s West End as a 700-foot-tall skyscraper, but has not submitted any formal plans.