Criticism by federal legislators is mounting against Indian outsourcing firms that use the H-1B visa foreign worker program to staff their U.S. operations. Critics claim that the Indian firms skirt regulations and use the visas to train workers in the U.S. to facilitate moving jobs offshore.

A government list obtained by InformationWeek of the top 200 companies receiving H-1B visas for foreign workers last year reveals that five of the top 10 were Indian outsourcers. The complete list of 200, however, shows a mix of foreign companies, U.S. technology vendors, and American universities. Microsoft is number three on the list, IBM number eight, and Oracle USA number nine. The New York City Public School system ranks twenty-second on the list, with 642 H-1B visas received last year.

Earlier this week, U.S. Sens. Dick Durbin (D-Ill.) and Chuck Grassley (R-Iowa), both members of the Senate Judiciary Committee Subcommittee on Immigration, sent letters to the CEOs of nine Indian firms asking for details about how they use their H-1B visas. The companies, including Infosys, Satyam, Tata Consultancy Services, and Wipro, are among the top users of the visas.

Last year, the nine Indian firms collectively were issued 19,512 of the 65,000 H-1B visas granted, according to the list. (In addition to the 65,000 granted annually, the U.S. also issues H-1B visas to 20,000 foreign students who received advanced degrees from U.S. universities.)

As of press time, none of the nine Indian companies has responded to the Durbin-Grassley letters, according to a Durbin spokesman. However, a statement by the National Association of Software and Services Companies, an organization that represents Indian IT firms, defended the practice:

"The Indian IT industry and NASSCOM do not see this as an immigration-related issue but one related to international trade, and would urge that work permits and intra-company transfers should not be intermingled and confused with immigration. Work permits are primarily a tool for facilitating trade and allow global companies to bring key staff to the US on temporary assignments, just as US staff often travel across the world for temporary assignments and this is clearly different from immigration."

Although H-1B visas are most frequently used to employ foreign-born technology workers, it's important to note that the visas also are used to hire professionals in other occupations, including nurses and other health-care workers, university professors, lawyers, engineers, and architects.