BEIJING, May 13 -- The Chinese Ministry of Commerce made a preliminary determination on Tuesday that Indian companies are dumping single-mode optical fibers and will impose provisional anti-dumping measures.

An investigation, which started in August, found that their dumping activities were damaging the interests of Chinese optical fiber producers, and that there was causal link between the dumping and the damage caused.

The ministry told domestic importers of India-made single-mode optical fibers to pay cash deposits to customs starting from May 14. The deposit rate ranges from 13.7 percent to 51 percent of the value of their imports.

The Indian fiber makers include Sterlite Technologies Limited, Birla Furukawa Fibre Optics Limited, Corning Technologies India Private Limited, Aksh Optifibre Limited and Finolex Cables Limited among others.

Single-mode optical fibers are used to make telecommunication equipment.