Private equity firm MidOcean Partners invested in The Planet Group, a provider of staffing and consulting in the life sciences and diversified energy and engineering markets. The terms of the transaction were not announced.

MidOcean is a former investor in System One, which ranks among the largest staffing firms in the US. It exited its investment in System One in October 2016. The private equity firm reported it worked closely with its own management resources when evaluating Planet, including Jon Chait, who formerly served as chairman and CEO of Hudson Global Inc. and CFO of Manpower Inc.

The Planet Group consists of six related entities, including Planet Pharma, and is aimed at serving firms in the life sciences, diversified energy and engineering, healthcare, and digital marketing industries. The Planet Group was founded in 2009, and is headquartered in Chicago.

Planet founders CEO Michael Stomberg and CFO Timothy Bauwens will continue to lead the company and will own a stake in the company.

“MidOcean has tremendous resources and experience building successful business services platforms with founder-owned businesses and a deep understanding of the professional staffing industry which makes them an ideal partner for Planet,” Somberg said. “This partnership with MidOcean will enable us to dedicate additional resources to build out our existing infrastructure and expand Planet’s offerings into other professional service areas both organically and through M&A activity.”