Moody’s said it may downgrade AT&T;’s debt.

The debt-rating company said it is also reviewing the rating of American Telephone & Telegraph Co.’s preferred stock for possible downgrading. “The rating review is prompted by the disappointing performance shown by AT&T; in its attempt to enter more competitive high-tech markets,” Moody’s said. Earlier this month, Standard & Poor’s said it would leave its rating for AT&T; unchanged at AA, its second-highest rating.