Major Japanese companies are buying back more of their own shares to prop up their sagging stock prices as the equity market continues to slump.

The buyback plans that have been announced since April by companies listed on the first section of the Tokyo Stock Exchange involve 4.2 trillion yen' worth of shares, or twice as much as was repurchased in all of fiscal 2001.

Among them are heavyweights such as Sony Corp. and Toyota Motor Corp.