Optus lifted its net profit more than 40 per cent during the December quarter despite a slide in revenue from mobile customers.

The telco made a net profit of $227 million for the three months to December 31, up from $160 million for the same period a year ago.

That was despite a five per cent slide in revenue, which Optus attributed to a mandated reduction in termination fees, lower equipment revenues and service credits associated with device repayment plans.

Optus said the number of customers on its 4G network rose more than 30 per cent during to quarter to 1.8 million.

Optus boss Kevin Russell said the company was also working to improve customer satisfaction,

He said the company had seen a 50 per cent reduction in customer complaints to the Telecommunications Industry Ombudsman during the September quarter.

“Our focus at Optus is on delivering sustainable profit growth and making significant improvements in the experience we deliver for our customers,” he said.

“This quarter has seen great progress in both these areas.”