Nikkei tumbles on global political concerns, exporters suffer
* Nikkei falls 2.1 pct, Topix down 2 pct
* Global political worries, firmer yen hit blue-chips
* Hedge funds take profits before PM Abe's tax decision
TOKYO, Sept 30 (Reuters) - Japan's Nikkei average shed more than 2 percent on Monday morning as blue-chip exporters and financials lost ground after concerns over a possible U.S. government shutdown and Italy's political crisis sent the dollar to a one-month low against the yen. The benchmark Nikkei was down 2.1 percent, or 315.34 points, at 14,444.73 in midmorning trade, on track for its biggest one-day fall since Aug. 20. But it is still up 8 percent this month, heading for its first monthly gain in five months. "Hedge funds are shorting recent gainers to lock in profits ahead of a big day tomorrow, when the prime minister will deliver his long-awaited decision," said Kyoya Okazawa, head of global equities and commodity derivatives at BNP Paribas in Tokyo. Prime Minister Shinzo Abe is expected to make an announcement about the government's economic growth and tax strategy on Tuesday. Global investors were wary after political wrangling in the U.S. Congress over the weekend made it increasingly unlikely that Republicans and Democrats will agree to fund the government before the fiscal year ends at midnight on Monday. In Italy, Prime Minister Enrico Letta said he would go before parliament on Wednesday for a confidence vote after ministers in Silvio Berlusconi's centre-right party pulled out of his government at the weekend. "Ahead of major event risk, U.S. political gridlock provided a good excuse for traders to do some profit-taking, but I think some investors will see the declines as dip-buying opportunities," Okazawa added. The dollar fell as low as 97.53 yen on trading platform EBS early Monday, its weakest level against the yen since Aug. 29. A firmer yen tends to make Japanese exports less competitive in the global market. Toyota Motor Corp dropped 2.5 percent and was the third-most traded stock by turnover on the main board. Honda Motor Co Ltd and Mitsubishi Motors Corp shed 3 percent and 2.7 percent, respectively. The broader Topix dropped 2 percent to 1,193.42. Mizuho Financial Group dropped 3.6 percent after the banking regulator chided its banking unit for failing to take sufficient action against loans it had extended to members of organised crime networks. It was the second most-traded stock. Other financials were also weak, with Nomura Holdings Inc dropping 3.7 percent and Mitsubishi UFJ Financial Group Inc slipping 2.8 percent. The benchmark Nikkei is still up 39 percent this year.