NEW YORK — Verizon's profit sunk 20 percent in its first quarter as it lost subscribers for its wireless cellphone service.

Shares dropped more than 2 percent in Thursday premarket trading. The stock has fallen more than 8 percent since the beginning of the year.

The New York company said that it lost 307,000 wireless subscribers who are billed each month, the more lucrative kind of wireless customer. Verizon said it would have lost even more subscribers during the first three months of the year if it didn't launch its unlimited wireless service in February. Last year during the same period, it added 640,000 subscribers.

Verizon Communications Inc., the largest U.S. cellphone carrier, is facing increased competition from rivals Sprint and T-Mobile who have been offering cheaper plans. Verizon brought back unlimited plans in February, hoping to attract new subscribers.

For its Fios service, Verizon added 35,000 internet subscribers, lost 13,000 cable subscribers and lost 8,000 voice subscribers.

Overall, the company reported net income of $3.45 billion, or 84 cents per share, for the three months ending March 31. That's down from $4.43 billion, or $ 1.06 per share, in the same period a year ago.

The results fell short of Wall Street expectations. Analysts surveyed by Zacks Investment Research called for earnings of 98 cents per share.

Revenue fell 7 percent to $29.81 billion, missing analyst expectations of $30.5 billion, according to Zacks.