The line has gone dead - or it seems to be heading that way with a new report revealing landline calls are rapidly declining.

The Commerce Commission has released its annual Telecommunications Monitoring Report which shows the number of residential local calls has halved in the past two years.

Telecommunications Commissioner Stephen Gale said New Zealand's telco market was more competitive than other OECD countries.

"Despite competitive pricing, retail telecommunications is a priority area for the commission because of our ongoing concerns about service quality and the growing number of consumer complaints we are receiving."

Mobile phone calls were on the rise, which Dr Gale said was attributed to the convenience and inexpensiveness of mobiles.

However, text messaging was declining as more consumers turned to online messaging services such as Facebook Messenger, iMessage and Viber, he said.

Fibre connections had increased up to 60 per cent in the past year with almost half a million homes and businesses taking up fibre broadband.

The average broadband download speed also increased by 40 per cent in the 12-month period and data usage had almost doubled, the commission found.

The Telecommunications Monitoring Report is annually produced to monitor the competition, development and performance of the market.