Doherty, an Edina staffing firm that has ridden a wave of demand for temporary workers over the past three decades, is selling off the human resources management portion of its business to a company in Florida.

Oasis Outsourcing in West Palm Beach, Fla., which claims to be the largest privately owned professional employer organization in the country, purchased Doherty Employer Services. Terms weren't disclosed.

The business provides HR services such as benefits administration, payroll processing, employment compliance, training and workers' compensation management.

Oasis CEO Mark Perlberg said the deal will help his company expand its Midwest presence. Rebecca Woods, a Doherty manager, will be regional vice president responsible for the region.

Doherty Staffing Solutions, which recruits and places workers with companies, will remain a stand-alone business.

The company was started by Tim Doherty, who borrowed $25,000 from his father in 1980 ($72,000 in today's dollars) and opened a temporary staffing office with three employees, including him and his mother.

He lost $2,500 the first year but has been profitable ever since. Doherty's wife Valerie, a lawyer, joined the firm in 1984 and is now chief executive. The company has offices in Minnesota and a presence in Wisconsin and northern Iowa.

"We are thrilled to enter into this relationship with Oasis," Valerie Doherty said in a statement. "I'm confident that our clients will benefit from this affiliation in a number of ways, while enjoying the same high level of service that Doherty Employer Services employees have always provided."

The Doherty Employer Services sales and service team will continue to work out of the Minneapolis location, providing clients with uninterrupted service, the firms said.

Oasis serves almost 200,000 employees and 6,000 clients nationwide. Founded in 1996, it provides human resources services, employee benefits administration, health care reform support, payroll and tax administration, risk management services and staffing solutions to small- and medium-sized businesses throughout the U.S.