AT&T revenue and earnings slipped in the first quarter from a year earlier, but the real news was a slowdown in subscriber growth for its postpaid phone plans, which caused the stock to slump in premarket trading Thursday.

Overall, AT&T reported earnings of 60 cents per share after stripping out certain one-off expenses, slightly higher than the 58 cents predicted. Revenue of $30.1 billion was slightly lower than expectations of $30.2 billion. 

Source: finance.yahoo.com