strongKolkata:/strong Tata Steel has planned to merge Tinplate Company of India Ltd and Tata Sponge Iron Ltd with itself. A company like Tinplate is like an extension of our steel plant. Tata Steel's cold rolling and coating is done there. But for some historical reasons they have remained as separate companies, Tata Steel managing director H M Nerurkar said on Thursday. Such plants remained as divisions the world over, he said citing examples of Nippon Steel and Arcelor Mittal. [caption id=attachment_393049 align=alignleft width=380