Vodafone New Zealand has posted loss of NZ$121 million for the year ended March 31, 2015, significantly up from the NZ$28 million recorded in 2014.
The company, which bought TelstraClear for NZ$840 million in 2012, also recorded a decline in revenue, from NZ$2.05 billion to NZ$1.96 billion.
The TelstraClear acquisition was financed by an inter-company loan from Vodafone Group. This year's accounts show Vodafone New Zealand owed its parent NZ$807 million in principal and NZ$700 million in accumulated interest repayable in the 2016 financial year.
A further NZ128 million was owed to an entity called Vodafone Overseas Finance, repayable in October 2017.
Finance costs for the debts were NZ$137.3 million for the period, up from NZ$130.6 million, indicating an interest rate on the inter-company loans of around 8.4 percent.
Vodafone NZ chief executive Russell Stanners said he was comfortable with the company's performance but would like to see the top line return to growth.
On top of the costs of acquiring and integrating TelstraClear, prices in the mobile and fixed line markets had also come under pressure, he said.
In June, Vodafone New Zealand also acquired specialist fixed line broadband provider Worldxchange.