Revenue rose 14% at Paychex Inc. (NASD: PAYX) in its fiscal third quarter ended Feb 28.

The Rochester, NY-based firm in December acquired Oasis Outsourcing Acquisition Corp., one of the largest professional employer organizations in the US, for a purchase price of $1.2 billion. Revenue in Paychex’s “professional employer organization and insurance services” segment rose 65% in its third quarter; excluding the acquisition of Oasis, the year-over-year increase was approximately 17%, driven by growth in clients and client worksite employees across its combined existing PEO business.

Paychex’s “PEO and insurance services revenue” includes PEO businesses such as Paychex Business Solutions LLC and HR Outsourcing Holdings Inc. as well as revenue from its insurance agency.

Paychex noted double-digit growth in the number of client worksite employees served, resulting from demand for its existing PEO services and growth within its client base. Insurance services revenue growth resulted from an increase in the number of health and benefit clients and applicants, offset by softness in the workers’ compensation market as state insurance fund rates declined.

Guidance

Excluding the anticipated impact related to the acquisition of Oasis, Paychex forecasts PEO and insurance services revenue to be up 18% to 20% in this fiscal year compared to last. The inclusion of Oasis, which was completed during the third quarter, is expected to have an incremental impact to total revenue in the range of $155 million to $175 million for fiscal 2019.

Share price and market cap

Paychex shares fell 1.73% to $78.72 at 11:20 a.m. Eastern time; the company had a market cap of $28.76 billion, according to FT.com.