By Joshua Hunt
TOKYO, May 2 (Reuters) - Japanese stock indexes tumbled to near a three-week low on Monday after the yen hit a fresh 18-month high against the dollar, hurting the profit outlook for exporters and other shares that benefit from a weaker yen.
The Nikkei share average .N225 ended the day 3.1 percent lower at 16,147.38, its lowest close since April 12.
The yen climbed to 106.14 yen per dollar after the U.S. Treasury put Japan on a new currency monitoring list along with four other countries that have large trade surpluses with the United States. The report could make it harder for Japan to intervene in currency markets to stem the yen's gains. ID:nW1N17G004
Japan's major automakers, which rely heavily on export sales for profits, underperformed the sagging Nikkei index. Toyota Motor Corp 7203.T shares fell 3.8 percent while Nissan Motor Co Ltd 7201.T tumbled 5 percent and Honda Motor Co Ltd 7267.T declined 4 percent.
Disappointing corporate earnings and forecasts further weighed on Japanese indexes. Sony Corp 6758.T fell 4 percent after reporting an annual loss in its crucial image sensor business, while Panasonic Corp 6752.T slid 7.4 percent on weaker sales. ID:nL3N17V2MJ
Telecommunications giant NTT Docomo Inc 9437.T bucked the day's weakness, gaining 4.9 percent on strong earnings and a solid profit forecast. ID:nL3N17Z1GN
The broader Topix .TOPX declined 3 percent to 1,299.96 and the JPX-Nikkei Index 400 .JPXNK400 slid 3.1 percent to 11,749.49. (Editing by Richard Borsuk)