On Assignment Inc.’s (NASD: ASGN) acquisition of Apex Systems boosted the firm’s top line in the third quarter when revenue jumped to $388.3 million, up 139.1 percent from the same period in the previous year. However, the Calabasas, Calif.-based technology and healthcare staffing provider reported third-quarter revenue rose 14.3 percent in its other businesses excluding Apex.

On Assignment acquired Apex in May. Apex ranked as the 17^th-largest U.S. staffing firm based on 2011 revenue, and it also ranked on Staffing Industry Analysts’ 2012 list of fastest-growing staffing firms.

Apex’s third-quarter revenue totaled $202.7 million, representing 52 percent of On Assignment’s total third-quarter revenue.

Year-over-year third-quarter revenue increases in other business units at On Assignment include:

• Oxford, which provides IT and engineering staffing, revenue increased 25.7 percent to $88.1 million.
• Physician staffing revenue rose 17.5 percent to $27.5 million.
• Allied healthcare revenue rose 32.9 percent to $15.6 million.
• Nurse travel revenue dropped 10.2 percent to $ 13.8 million.
• Life sciences revenue slipped 2.8 percent to $40.6 million.

Third-quarter gross margin was 30.7 percent compared with 33.6 percent for the third quarter of 2011. The company attributed the year-over-year decline in gross margin to the inclusion of Apex. Excluding Apex Systems, the combined gross margin for the other business segments was 33.5 percent, down slightly from the 33.6 percent in the third quarter of 2011. Third-quarter gross margin for Apex Systems was 28.1 percent.

Net Income was $17.4 million, up 124.4 percent from $7.8 million in the third quarter of 2011.

On Assignment Inc. (NASD: ASGN)
 For the third quarter ended Sept. 30, 2012, compared with the year-ago quarter.
 Revenue: $388.3 million, +139.1 percent
 Net income: $17.4 million, +124.4 percent