Vocus Group, which owns the iPrimus and Dodo broadband brands, has assured investors it will not breach its debt covenants in the next 12 months after delivering a stinging $1.46 billion loss for 2017.

Vocus is planning to sell assets and has canned its dividend for the second half of 2017 and may do the same again for the first half of 2018 to shore up its balance sheet after a horror year.

Along with booking a loss driven by high finance costs and a swingeing $1.53 billion writedown on Wednesday, Vocus also revealed its chairman David Spence is stepping down.

His retirement comes just days after it was revealed two private equity suitors - Kohlberg Kravis Roberts (KKR) and Affinity Partners - walked away from bidding for the telco, sparking a 16.5 per cent share price plunge.

Vocus chief financial officer Mark Wratten told analysts he would not be seeking lender relief from the covenants over the group's debt.

"Our covenants certainly will tick upwards as we get to the half year ... and then come back down in the second half," Mr Wratten said.

"Those asset sales certainly we do want to look at those as a way of supporting and strengthening our balance sheet, as we move into full-year 2019 I would want to see us de-lever," he said. Vocus has net debt of $1.03 billion.

Underlying profit came in at $152.3 million, a 50 per cent increase on the prior year, but below the company's guidance of underlying profit of between $160 million to $165 million range given earlier this year.

Vocus is now tipping its underlying profit for 2018 is expected to be in the range of $140 million and $150 million as competition on costs, particularly in regards to the NBN, begin to bite.

Morningstar analyst Brian Han said he did not think Vocus had a "debt problem" despite a tough year.

"There is some breathing space in the earnings guidance they have given and with the CFO's primary focus being on the cash flow I think it is manageable."

Chief executive Geoff Horth said he expected further increases in wholesale costs in 2018, but is planning to relaunch its iPrimus brand.

The iPrimus and Dodo brands increased its market share in the National Broadband Network to 7.3 per cent from 6.4 per cent during 2017, Mr Horth said.

"We have some prospects of mitigating those increases by changing the mix of sales - with iPrimus relaunch we'll drive more of our share into that higher ARPU (average revenue per user) product," Mr Horth said.

Vocus shares closed up 0.76 per cent at $2.64.