Japan's key Nikkei stock index dived more than 400 points Friday.

The 225-issue Nikkei Stock Average lost more than 500 points atone point before ending down 406.51 points, or 2.37 percent, at 16,764.09, the lowest close since mid-March.

The Topix index of all First Section issues on the Tokyo Stock Exchange was down 49.88 points, or 2.96 percent, to 1,633.93, also the lowest since mid-December last year.

The fall was mainly aroused by overnight falls in European and U.S. equity markets. On the First Section, 1,445 issues declined against 235 advancing with 44 ending the day unchanged.

Nippon Steel was the day's volume leader, down 31 yen to 826 yen.

Mizuho Financial Group, the most heavily traded issue by value during the day, shed 12,000 yen to 707,000 yen.

Trading volume on the main section decreased to 3,354.13 million shares from Thursday's 3,810.44 million shares.

The TSE's Second Section index fell 99.39 points, or 2.50 percent, to 3,872.84 on a volume of 59.87 million shares.

On the Osaka Securities Exchange, the near-term September Nikkei 225 index futures contract fell 470 points to 16,750.