System One, which ranks among the largest engineering staffing firms in the US, acquired IT staffing provider Cohesion as well as The Rowland Group, a staffing provider with offices in Tulsa, Oklahoma and Houston.

System One acquired Cohesion through its ALTA IT Services LLC division. The deal closed Aug. 5; terms of the transaction were not announced.

Cohesion, which will integrate into ALTA, has offices in Baltimore and Cincinnati. Its services include workforce solutions and agile consulting services to the government and private sectors, including infrastructure, application support, business intelligence, quality assurance and software testing, and agile consulting.

System One also acquired The Rowland Group, which provides staffing in the energy, engineering, IT and finance/accounting segments. It will continue to operate under the Rowland brand as a division of System One.

“The Rowland Group acquisition deepens our expertise within multiple business areas and expands our national presence,” said Troy Gregory, president and CEO of System One.

Terms of the deal were not announced; the acquisition closed on July 8.

System One, based in Pittsburgh, provides staffing in energy, engineering, IT, commercial, scientific and clinical, legal, marketing and other segments.