HCL Technologies Ltd. has warned that a historic U.S. rating downgrade over the weekend may lead to a temporary slowdown in business in the industry's biggest outsourcing market as fears of a double-dip recession sparked a sell-off in India's technology stocks.

The downgrade may lead to a slowdown in business in the immediate term, Shami Khorana, president of HCL Americas, said in an interview late Sunday. Clients in the U.S. might feel cost pressures immediately and go slow in their spending decisions, Mr. Khorana added.