Sky UHF network customers have until the end of next month to switch over to the pay-TV provider's digital service before it turns off the network.

The broadcaster announced early last year that it would no longer be accepting new UHF subscribers as the company's transmitting equipment, installed in 1990, started falling apart.

The transmitters generally last for about 15 years but no one makes the equipment anymore and the parts are hard to find.

Sky chief executive John Fellet had said UHF was either going to be turned off or fall apart and the firm started pushing to convert its customers to its digital offerings.

The network has now committed to closing the UHF system, starting on August 31 in Taupo. The company hopes to have the process completed throughout the country within six months.

Sky spokesman Tony O'Brien said UHF had about 300,000 subscribers in 1995 and the company had reduced that to about 25,000 customers.

He said the digital option, which has run since 1998, had "much more variety, stacks more channels".

"As we had to close it down we're just moving them across, giving them a very compelling offer to move across to our digital, and it's going exceptionally well."

Mr O'Brien said the digital service was not a more expensive option but was a "completely different network with a whole host of different options and package choices for [customers] so it depends what they pick".

The broadcaster would send out installers to every UHF home to put up new satellite dishes for the digital network at no cost to the customer, he said.

Sky moved its live broadcasts of the Warriors league team from Sky Sport 1 to digital-only Sky Sport 2 to move people away from the now-decrepit technology. About 10,000 people migrated once that happened.

Sky plans to hand its UHF and radio spectrum back to the Government and trade them for digital terrestrial bandwidth.