Du Pont Co. announced that it will...

Du Pont Co. announced that it will buy and retire up to 20 million of its own shares, or about 8% of the outstanding stock, in a bid to enhance the price of the stock. Du Pont, the nation’s biggest chemical concern, also raised its quarterly dividend 10 cents a share to $1.05 and announced preliminary full-year earnings of $9.11 a share, up from the $7.93 a share it earned in 1987.