He said the company's policy was that it did not comment on business decisions that affected its staffing numbers.
"We disclose our staff numbers on a biannual basis as part of our financial reporting and we don't tend to comment beyond this."
Spark's staff numbers have risen in the past year.
In December 2016 it had 5943 full-time workers, up from 5324 in December 2015.
Spark reported earnings before interest, tax, depreciation and amortisation of $471 million in the six months to December 31, up from $455m in same prior period.
Arie Dekker, head of research at First New Zealand Capital, said he had not heard any specific rumours on significant staff cuts but there was a general expectation that Spark would continue to rationalise its staffing levels over time.
Dekker said Spark had a very strong balance sheet but the composition of the business meant it continued to face downward pressure on revenues in legacy parts of its business amid strong competition which meant it had to ensure it had the right cost base for the size of its operations.
"Spark has been investing in systems to enable it to reduce some of the workload that has been done manually.
"Over time we would expect some of the things that Spark has managed manually to be replaced with managed networks and customer self-management interfaces.'
The Spark spokesman said the technology world in which Spark operated was changing faster than ever.
"As a consequence, our business has changed enormously in recent years and the one thing we can say for sure is that it will continue to do so.
"Our customers expect us to be offering the best deals at ever better prices, improving their service experiences and making it easier and simpler for them to use our products and services and to get help from us.
"That means as a business we must do even more to tightly manage our operating costs and radically simplify our products, tools and processes, taking advantage of the latest and best digital technologies."
