AT&T fell by 3.21% to trade at $27.40 by 10:09 (15:09 GMT) on Monday on the NYSE exchange.
The volume of AT&T shares traded since the start of the session was 12.24M. AT&T has traded in a range of $27.39 to $28.29 on the day.
The stock has traded at $30.4000 at its highest and $27.3900 at its lowest during the past seven days.
