The benchmark Nikkei index at the Tokyo Stock Exchange fell 170.32 points to 8,665.20 by the lunch break. The Topix index of all first-section issues lost 14.36 points, or 1.90 percent, to 740.14. "The Greek public doesn't like the bailout package involving austerity measures. Optimism ahead of the G20 meeting (on Thursday) has melted away," said Fumiyuki Nakanishi, general manager of investment and research at SMBC Friend Securities. The Nikkei could fall to 8,500 later in the day, he added. The eurozone was plunged back into a fresh crisis and markets sent into a panic on Tuesday when Greek Prime Minister George Papandreou issued a surprise call for a referendum on the hard-won debt rescue package agreed last week. Japanese Finance Minister Jun Azumi said Wednesday the referendum plan had "confused people". The Group of 20 advanced and developing nations will discuss the issue when they start a meeting in France on Thursday, Azumi told reporters. US stocks dived Tuesday, with the blue-chip Dow Jones Industrial Average losing 2.48 percent to finish at 11,657.96 after sharp falls in Europe. The euro was at $1.3697 in Tokyo midday trade, almost unchanged from New York late Tuesday. It fell to 107.01 yen from 107.29. The euro rose into the $1.42 level last week after a summit of European leaders reached a comprehensive deal to resolve the months-long crisis, starting with a new Greek debt reduction and austerity deal. The dollar edged down to 78.10 yen from 78.34 yen. Nomura Holdings tumbled 3.40 percent to 284 yen after the company posted its first loss in more than two years in the July-September period as the impact of market turbulence and the eurozone crisis hit hard. Hitachi fell 0.46 percent to 424 yen after its July-September net profit fell 33 percent on-year.