Robert Half International Inc.’s (NYSE: RHI) first-quarter revenue rose 15.3 percent on a year-over-year basis to $1.02 billion. The Menlo Park, Calif.-based professional staffing firm’s fastest-growing segements included Robert Half Technology and Robert Half Finance & Accounting.

U.S. staffing revenue in the first quarter was $652 million, up 20.8 percent on a year-over-year basis, the company reported in a conference call with analysts. U.S. temporary and consulting revenue rose 20.2 percent in the first quarter, and U.S. permanent placement revenue rose 29.3 percent.

Revenue from international staffing operations was $260 million in the first quarter, a 9.0 percent year-over-year increase on a same-day and constant currency basis. International temporary and consulting revenue rose 7.8 percent, and international permanent placement revenue rose 16.5 percent — both on a same billing day constant currency basis.

“We were pleased with our financial results for the quarter, which were the result of continued strong demand for our specialized staffing and consulting services,” said Chairman and CEO Harold “Max” Messmer Jr. “This is the seventh straight quarter the company has reported double-digit, year-over-year revenue growth.”

Each of the company’s segments reported year-over-year increases in first-quarter revenue with the largest increases in Robert Half Finance & Accounting and Robert Half Technology:

• Accountemps, up 16.7 percent to $385.4 million
• OfficeTeam, up 13.7 percent to $200.5 million
• Robert Half Technology, up 19.8 percent to $115.6 million
• Robert Half Management Resources, up 15.0 percent to $128.1 million
• Robert Half Finance & Accounting, up 22.6 percent to $82.9 million
• Protiviti, up 4.4 percent to $102.9 million

Robert Half’s first-quarter gross margin improved to 39.6 percent from 38.4 percent in the year-ago quarter.

First-quarter net income rose 81.0 percent to $48.3 million from $26.7 million in the first quarter of last year.

Robert Half International Inc. (NYSE: RHI)
For the first quarter ended March 31, 2012, compared with the year-ago period.
Revenue: $1.02 billion, +15.3 percent
Net income: $48.3 million, +81.0 percent