TOKYO, March 19 (Xinhua) -- Tokyo stocks closed mixed Friday, with the Topix index climbing to a 30-year high after the Bank of Japan opted to purchase only Topix-related exchange-traded funds (ETFs), while the benchmark Nikkei stock index fell on concerns over U.S. corporate borrowing costs and equity valuations.

The 225-issue Nikkei Stock Average dropped 424.70 points, or 1.41 percent, from Thursday to close the day at 29,792.05.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, added 3.70 points, or 0.18 percent, to finish at 2,012.21, marking its highest closing level since April 1991.

Mining, and information and communication issues led notable decliners, while marine transportation and bank issues comprised those that gained the most by the close of play.