Fourth-quarter revenue rose across most business lines at On Assignment Inc. (NYSE: ASGN), although year-over-year growth is estimated to be lower in the first quarter. Fourth-quarter revenue was $401.7 million at the Calabasas, Calif.-based staffing provider, up 148.3 percent on a year-over-year basis. However, the company acquired IT staffing firm Apex Systems in May 2011. Fourth-quarter revenue rose 20.0 percent excluding Apex.

Revenue by division includes:

• Apex posted revenue of $207.6 million in the fourth quarter, representing more than half of On Assignment’s revenue for the quarter. Apex’s gross margin was 27.3 percent in the fourth quarter. On Assignment estimates year-over-year revenue growth of 11 percent for Apex in the first quarter.
• At the company’s Oxford division, which also provides technology staffing, fourth-quarter revenue rose 26.9 percent on a year-over-year basis to $90.4 million. However, the company estimates Oxford’s revenue growth will be in the low teens during the first quarter.
• Allied healthcare staffing revenue rose 32.0 percent to $16.1 million in the fourth quarter. The company estimates first-quarter revenue growth will be in the mid to high teens on a year-over-year basis.
• Nurse travel revenue rose 54.4 percent to $21.3 million. However, the company announced today that it sold the division for $31.0 million.
• Physician staffing revenue rose 10.0 percent to $26.1 million in the fourth quarter. On Assignment estimates physician staffing revenue will rise in the low, single-digits in the first quarter.
• Life sciences revenue contracted 1.5 percent in the fourth quarter to $40.3 million. The company also forecast a slight contraction in year-over-year growth for the first quarter.

Fourth-quarter gross margin contracted to 30.2 percent from 33.1 percent in the year-ago quarter. Excluding Apex, fourth-quarter gross margin improved to 33.2 percent.

Net income rose 50.9 percent to $11.3 million from $7.5 million in the fourth quarter of 2011.

On Assignment Inc. (NASD: ASGN)
For the quarter ended Dec. 31, 2012, compared with the year-ago quarter
Revenue: $401.7 million, +148.3 percent
Net income: $11.3 million, +50.9 percent

For the full-year ended Dec. 31, 2012, compared with the previous year.
Revenue: $1.24 billion, +107.6 percent
Net income: $42.7 million, +75.5 percent