Nikkei falls as exporters and financials weigh, GS Yuasa tumbles

* Euro-sensitive exporters underperform * GS Yuasa tumbles on Mitsubishi Motors' battery overheating By Ayai Tomisawa TOKYO, March 28 (Reuters) - Japan's Nikkei share average dropped on Thursday with exporters and financials falling on profit-taking as sentiment was hit by weakness in the euro due to concerns about Italy's funding costs and the rescue deal for Cyprus. The Nikkei dropped 1.6 percent to 12,298.61 by the midday break, staying below its five-day moving average of 12