Investing.com - (LON:BT) plunged Tuesday as probe into Italian business shows "inappropriate behavior."
BT shares were down 18.15% at £313.10. at 04:30 ET
In a statement, BT said an extended probe showed errors in accounting and management decisions.
BT increased the writedown in earnings to £530 mn from £145 mn in the current fiscal year.
Further writedowns are on the cards for next year's earnings.
BT Italy suspends number of senior executives. New CEO to take over next month.