TOKYO, March 7 (Reuters) - Japan's Nikkei share average dropped on Wednesday after free-trade advocate Gary Cohn resigned as U.S. President Donald Trump's top economic adviser, fanning fears Washington will proceed with tariffs, pushing the steelmaker index to an eight-month low.
Nikkei average dropped 0.8 percent to 21,252.72, not far from 4-1/2-month low of 21,042.09.
Steelmakers became the worst-performing sector again, with Topix Iron & Steel index shedding 2.1 percent to hit an eight-month low, having lost 7.8 percent since U.S. President Donald Trump announced his tariff plan, more than twice as much as fall in the broader market.
About two-thirds of the stocks on the main board declined but about 30 percent managed to make gains, with small-cap shares dipping just 0.5 percent, outperforming larger shares. (reporting by Tokyo Markets Team, Editing by Sherry Jacob-Phillips)