Verizon Communications on Tuesday posted a surprise rise in wireless subscriber additions as more users upgraded their mobile phones to access its super-fast 5G network in a highly competitive market.

The carrier has been trying to aggressively build out its 5G network in the United States, in hopes that it would give it an edge over cheaper offerings from rival telecom players such as T-Mobile.

Verizon, whose plans typically cost more than its peers, added 8,000 net monthly bill-paying wireless phone subscribers in the second quarter, compared with estimates for a loss of 11,000, according to analysts polled by Factset.

Its results come as the sector is rattled by a Wall Street Journal report on July 9 that the company and AT&T were among several telecom operators that abandoned a sprawling network of lead-clad cables, which might have contaminated water and soil.

Verizon's total revenue fell 3.5% to $32.6 billion in the quarter ended June 30, missing analysts' estimates of $33.24 billion, according to Refinitiv data. (Reporting by Samrhitha Arunasalam in Bengaluru; Editing by Anil D'Silva)