Verizon Communications Inc. said it received more than 1,000 requests for information about its subscribers on national security grounds last year, in the company's first report on official requests to turn over customer data.

The U.S. telecom giant said it received between 1,000 and 1,999 so-called National Security Letters, which are requests for customer records that don't require approval from a judge or grand jury as long as the information is relevant to national security. Recipients of individual National Security Letters...