CHARLESTON, SC—Ranked as the number one rental apartment manager in the National Multifamily Housing Council‘s 2014 Top 50 listing, Greystar Real Estate Partners has grown even larger by acquiring its biggest competitor. The Charleston, SC-based company said Wednesday afternoon it had bought Dallas-based Riverstone Residential Group from London-based CAS Capital Ltd.

The acquisition brings Greystar’s management portfolio to more than 385,000 apartments across the US and overseas, including more than 176,000 managed by Riverstone. As a basis of comparison, what is now the second-largest manager in the annual NMHC ranking, Dallas-based Lincoln Property Co., has a portfolio of 153,445 units. Financial terms of the acquisition from CAS Capital were not disclosed.

Bob Faith, Greystar’s chairman and CEO, says that combining forces “makes us even stronger, especially in local markets where we are bringing together some of the most talented and experienced multifamily professionals in the industry.” In particular, the combination will bolster Greystar’s presence in the West. With a workforce now numbering about 10,000, Faith adds, “Our local teams are well resourced, and will now harness the power of our combined technology and service platforms to further expand our service offerings to our clients, partners and residents.”

The scale that Greystar has added via the Riverstone acquisition may not be the end of it, though. A Greystar spokeswoman tells, “In combining forces we expect to further enhance our organic growth, as we now have even greater depth of talent in each of our local markets.” She adds that Greystar will also continue to look for opportunities to grow through acquisition, “if the combination is strategic and culturally compatible.”

The Riverstone deal represents Greystar’s largest acquisition, but it’s far from the first. Over its 20-year history, the company has integrated a number of major operators, including the management arms of JPI, Archon and Glacier.