Paychex Inc. (NASD: PAYX), a payroll processing and professional employer organization firm, acquired HR Services Inc. and myStaffingPro, its software-as-a-service applicant-tracking suite. The Lima, Ohio-based company now operates as a wholly owned subsidiary of Paychex.

The deal closed at the end of last year and financial terms were not disclosed.

MyStaffingPro is a Web-based system that provides social recruiting, applicant tracking, and onboarding solutions. Launched in 1999, its applicant-tracking suite is used by more than 550 companies and provides technology for recruiting, qualifying, tracking and hiring applicants. The system is targeted to corporate recruiting departments but does service staffing firms.

“Paychex is focused on delivering solutions to our clients that combine innovative technology with superior customer service, while driving growth for the company and expanding the markets we serve,” said Paychex President and CEO Martin Mucci. “With this acquisition we are able to combine the myStaffingPro technology and expertise with Paychex resources to strengthen our portfolio of human resource service solutions, and provide an industry-leading applicant tracking and recruiting services solution for our clients.”