The number of H-1B visas that can be issued annually is at 65,000, plus an additional 20,000 set aside for foreigners who hold advanced degrees from U.S. universities. But while the total of available visas remains constant, the number issued to the major offshoring vendors is rising.

The four largest H-1B recipients last year are all based in India: Ltd., with 4,559 visas; ., with 2,678; ., with 1,917; and Tata. The number of visas issued to Infosys was identical to what it received in fiscal 2007, but Wipro, Satyam and Tata all saw increases.

In total, the top 10 IT services firms on the H-1B list received nearly 13,300 visas last year, almost 1,000 more than they were issued in 2007. Some of those companies are based in the U.S., such as Cognizant Technology Solutions Corp. But they all have substantial operations in India or other offshore locations.

With the overall because of the economic recession, there has been some backlash in Washington over corporate use of H-1B workers. The $787 billion economic stimulus plan signed into law by last week includes by financial services firms that receive federal bailout funds. But the restrictions don't affect outsourcing vendors that provide IT services to the financial sector.

In an interview last week, Srini Pallia, vice president and global head of business technology services at Wipro, said that if the restrictions increase on H-1B visa use, his company has a "Plan B" that would include hiring more workers in the U.S. "We definitely have people locally who will be on the project," he said.