One of Spark's top executives will leave in June.
The phone company said the head of its Home, Mobile and Business service Chris Quin would depart to pursue new opportunities.
Mr Quin would be replaced by Spark's Jason Paris.
Forsyth Barr analyst Blair Galpin said Mr Quin, who has been with Spark and formerly Telecom for over 20 years, including a stint as acting chief executive of Telecom, had done a good job at restoring the company's share in broadband and mobile markets.
"If you look back to the sort of last 12 to 18 months, basically things have turned around in the broadband space and they're back to sort of maintaining their market share there."
"If you look at the mobile space, they've obviously been gaining share in mobile," he said.
Spark had been cutting costs as part of its turnaround plans, and its chief executive, Simon Moutter, said once that was complete, it would move to expand revenue through a new programme to create an online platform to deliver new services to customers.
At Midday, Spark's shares had risen 4 cents to $3.39 each.