U.S. telco lost almost 400,000 phone customers before relaunching unlimited data tariffs.

Verizon lost 307,000 retail postpaid connections during the first quarter of 2017, as fierce competition from the likes of T-Mobile US took its toll.

That figure includes 289,000 phone losses, the telco revealed on Thursday. The situation would have been even worse had Verizon not reintroduced an unlimited price plan.

"The launch of Verizon Unlimited positively changed the trajectory of customer additions in the quarter," Verizon said. "Prior to the launch in mid-February, Verizon had a retail postpaid phone net loss of 398,000; after the launch, Verizon added 109,000 retail postpaid phone connections."

Verizon still ended March 2017 with more retail postpaid connections than it had 12 months ago, as its base rose 1.2% to 108.5 million. Retail prepaid connections grew 0.5% to 5.4 million.

However, the poor performance in the first quarter highlights the impact of aggressive offers from rivals like T-Mobile and Sprint.

Verizon’s Fios fixed-line business also reported mixed results.

It added 35,000 Internet connections, but lost 13,000 video subscribers during the quarter. It ended March with 5.7 million Internet connections and 4.7 million video subscribers, representing year-on-year increases of 3.3% and 0.1% respectively.

On the financial side, total operating revenues fell to $29.81 billion (€27.74 billion) from $32.17 billion a year ago. Wireless revenue came in at $20.88 billion, down from $22.00 billion, and wireline revenue fell to $7.88 billion from $7.92 billion.

Operating income declined to $7.18 billion from $7.94 billion in Q1 2016, while net profit fell to $3.55 billion from $4.43 billion.

For 2017, Verizon said it expects consolidated revenues and adjusted earnings per share to be broadly flat compared to 2016. The company said capex will be in the range of $16.8 billion-$17.5 billion.