Automatic Data Processing Inc. (NASD: ADP) named Jan Siegmund as its new CFO effective Nov. 5. In addition, the company reported today that revenue in its professional employer business rose 12.8 percent on a year-over-year basis to $448.9 million in its fiscal first quarter ended Sept. 30.

Upcoming CFO Siegmund currently serves as chief strategy officer and president, added value services. He will replace Chris Reidy, who has served as CFO since 2006. Reidy will remain available through calendar year-end to facilitate the transition.

Siegmund joined ADP in 1999. The company will consider internal and external candidates to fill the positions previously held by Siegmund.

Separately, the Roseland, N.J.-based firm reported first-quarter earnings with PEO revenue rising 12.8 percent. And average number of paid PEO worksite employees during the third quarter rose 11.2 percent to 269,000.

PEO services represent just one of ADP’s business lines, which also include non-staffing services. The company reported total first-quarter revenue of $2.64 billion, a 5.0 percent increase on a year-over-year basis.

First-quarter net earnings rose 0.9 percent to $305.3 million from $302.7 million first quarter 2011.

ADP expects PEO revenue to rise 13 percent to 14 percent in its fiscal year 2013.

ADP ranks as the second-largest PEO in the U.S.