The sale of GasValpo marks the first step of AGL's planned $2 billion asset sale to fund the acquisition of energy assets in New South Wales that are being privatised by the State Government.

"It is the first in what should be a series of non-core asset divestments," AGL managing director Michael Fraser said in a statement.

Fraser added that the sale would provide "balance sheet flexibility" to allow the company to participate in new opportunities emerging in Australian energy markets.

"GasValpo was always going to be the most challenging non-core asset for us to divest so it is particularly pleasing we have been able to start with the sale of this asset," he said.

In other news, the company has launched the AGL Energy Challenger, a new online service for industrial and commercial business customers to help them manage their energy usage and encourage energy efficiency.

The free service was developed in conjunction with energy consultancy Energetics and allows customers to evaluate their energy management practices and use of energy efficient technologies.

The service also provides a report on the business energy efficiency rating and a benchmark comparison to assess how others in the same industry perform, and a prioritised action plan.

It also indicates the potential energy savings that can be made by implementing the recommended measures.