Fierce competition in the US operator market led to number three player Sprint reporting a US$1 billion loss for the fourth quarter as it experienced the slowest customer growth of the country’s four major carriers.

Its loss of $1.04 billion was actually an improvement on the larger loss of $1.35 billion in Q4 2012, but compared with a net profit of $383 million in Q3 2013. Revenue hit $9.14 billion, an increase from the $9 billion in Q4 2012 as well as an improvement from $8.68 billion on a sequential basis.

Sprint managed nearly 477,000 total net additions in Q4 but, more importantly, the number of new contract customers shrank considerably, falling to just 58,000 new subscribers from 401,000 a year ago. The impressive 477,000 figure was made up of 327,000 net new subscribers from its wholesale operations and affiliates as well as 219,000 from its own prepaid operations.

Sprint is feeling the pressure from rival T-Mobile US, which has turned the screws on its rivals with its Uncarrier strategy. Speculation suggests Sprint (owned by SoftBank) is likely to mount an acquisition bid for T-Mobile in an effort to better compete with AT&T and Verizon.