The key Nikkei stock average closed on Wednesday below the psychologically important 11,000 line for the first time in nearly 17 years as Japanese investors became worried by signs of a further delay in a U.S. economic recovery.

The 225-issue Nikkei, which fell 85.61 points Tuesday, tumbled an additional 209.64 points, or 1.87 percent, to close at 10,979.76, ending below 11,000 for the first time since Oct. 20, 1984.

The broader Tokyo Stock Price Index (Topix) of all first section issues was down 23.39 points, or 2.03 percent, to 1,126.86.