India, May 3 -- Indian IT majors and industry bodies are growing increasingly worried about a proposed rule by the US Federal Communications Commission (FCC) that would restrict the use of offshore call centres by certain American companies - a move that could reshape one of the most significant sources of outsourcing revenue for companies that have made India the world's back office for American consumer businesses.

The FCC proposed the rule on March 26, releasing it the following day, with a public comment period opening after its publication in the Federal Register. Comments are due by May 26, with reply comments due by June 22.

The rule, framed by the FCC as a consumer protection and national security measure, floats three broad int...