Vodafone Australia may be poised to pull out of a transtasman billing project leaving Vodafone New Zealand to go it alone.

Speculation is mounting that Vodafone's huge transtasman billing project is behind schedule and may be scaled back to make it more manageable.

The billing project, known as SAM, aims to make New Zealand the processing centre for customer billing for Australia, Fiji and New Zealand.

It would contain the necessary enhancements needed for the billing of advanced next-generation services once the 3G network is launched.

Sources said Vodafone Australia was pulling out of the project to focus on getting its market share up after fierce competition from its Australian competitors. It was having customer-retention issues and would focus on those rather than billing.

However, Vodafone spokeswoman Leigh Owens said the regional billing project was on track in Australia and New Zealand with no plans to abandon it in either country.

Software contractors working on the project have said it is behind schedule.

Owens would disclose no details of the issues around the billing system with respect to the commercial arrangements with suppliers.

There are said to be problems with Vodafone New Zealand's existing billing system, which does not recognise some of the services the company is selling under its Vodafone Live brand.

Payments to content providers are being made based on estimates rather than actual sales.

When Vodafone launched its camera phone PXT service it was unable to bill for the service. The company capitalised on this by offering customers free PXT services until billing was sorted out.