Professional employer organization Oasis Outsourcing acquired Staff One HR. While Oasis currently has a presence in Texas, the deal expands its geographic footprint in the south-central region of the US.

Founded in 1988, Staff One HR provides human resources and related PEO services. It is headquartered in Dallas, with additional offices located in Tennessee, Colorado and Oklahoma.

The transaction closed Dec. 1; terms were not disclosed. Oasis Outsourcing will maintain the brand, and Staff One CEO Mark Sinatra will continue in his leadership role.

Staff One HR has 11,000 worksite employees, and the combined company will now count more than 8,000 clients and 260,000 worksite employees nationwide.

“Acquisitions of exceptional PEOs continue to be an important component of our overall growth strategy,” said Oasis Outsourcing President and CEO Mark Perlberg. “Staff One HR has a successful history of providing HR solutions to its clients. We are excited to bring our organizations together, capitalize on best practices and welcome the Staff One HR team and its clients to the Oasis family.”

Oasis Outsourcing in June acquired Arizona-based DHR Services Holdings LLC and its subsidiaries, which expanded its geographic footprint in the Western region of the US.

And in July, Oasis Outsourcing announced private equity firm Kelso & Company purchased a “significant” interest in the company. Stone Point Capital, which acquired the PEO in 2014, remains the majority owner of Oasis Outsourcing, with the remainder owned by Oasis management.