BRADENTON -- One of the state’s largest human resources and back-office solutions providers has been sold to Workforce Business Services.

Headquartered in downtown Bradenton, Employee Leasing Solutions has closed on the sale of all its Florida and California assets to WBS, a small industry competitor that just gained its operating license in November, the company announced Friday.

Terms of the deal were not immediately disclosed.

ELS President and founder Bill Mullis -- one of the pioneers in the industry, which has long had a strong presence in Manatee -- sold his stake in the company to pursue retirement.

In a letter sent to company employees and brokers late last month, Mullis said he expects a seamless transition. He also praised WBS President and CEO Robert Kelly, a longtime friend of Mullis’.

“At the end of the day, the biggest change for most will be writing your check to WBS in place of ELS,” he said in the letter. “Almost everything else will remain unchanged.”

Mullis founded Staff Leasing in the 1980s, one of the first professional employer organizations in Florida. He later sold the company, which is now known as Tri-Net, to open ELS in 2001.

WBS will retain the company’s leased space at the Bradenton Financial Center at 1401 Manatee Ave. W and most of the 120 ELS employees. WBS also is acquiring the ELS Florida offices in Jacksonville, Lake Mary, Lehigh Acres, Naples, Stewart, West Palm Beach and Ft. Lauderdale.

The company provides human resources, insurance, 401k and payroll services to nearly 1,000 smaller employers across the state, with a heavy focus on the construction industry.

WBS expects to process $350 million in payroll services this year.

“For a small guy with 10 employees, this can be very difficult,” said Daniel Johnson, vice president and general counsel for WBS. “We take that burden away.”

Josh Salman, Herald business writer, can be reached at 941-745-7095.