Cameron told International Longwall News that while selling Anvil Hill wasn't always on the cards, it had not interrupted the company's strategic direction. The deal was agreed on after Xstrata put forward an offer for the mine that was "too compelling for us to refuse."

"What the sale does, it brings forward the value we've created in the pre-development work at Anvil Hill ... to our shareholders immediately," Cameron said.

"Xstrata have operation synergies and coal blending and marketing synergies beyond what we have so they can pay more for the project. We make more money for our shareholders by selling the property at this stage than by developing and operating it.

"Similarly with Tahmoor - they [Xstrata] are upfront intending to offer more for our shares than we can realize by operating the mine and clearly we've turned it around, we've set it up very well for the future and they're paying upfront for the future of the mine."

Cameron said the financial gain of the sale of Anvil Hill and proposed sale of Centennial's 86% shareholding in Austral Coal's Tahmoor mine to Xstrata - amounting in more than $A1 billion to Centennial - creates opportunities for the company to pay down debt, boost operations at existing mines, return capital to shareholders and finally look at expansion opportunities.

He said the short term focus, however, was on sealing the sales and on increasing production at existing sites.

Production at the Mandalong longwall is expected to increase to more than 5 million tonnes a year as the mine embarks on production of its wider blocks.

Cameron said Mandalong's face width had increased from 115 metres to 150 metres on the larger blocks and the company was confident it could expand wider after making headway on subsidence management.

He added the company was looking at two alternative options for an upgrade of export infrastructure at the Mandalong mine site, currently requiring transport to the nearby Newstan complex to utilise the train loading and washery infrastructure.

"One option is to install a direct haul road to the Newstan infrastructure and the other is to build a purpose built washery and rail loading facility at Mandalong itself. Studies are well advanced at looking at the most efficient infrastructure option," Cameron said.

Mandalong will also benefit from gaining some of the longwall equipment from the soon to be put into care and maintenance mine Newstan in a bid to reduce down time during longwall moves.

Cameron said Newstan was on the second last of its longwall blocks.

Neighbouring Centennial operations Angus Place and Springvale will also be given a production boost. A new longwall is on order for the Angus Place site from suppliers Joy and DBT and the longwall face width has been expanded at Springvale.

"At Angus Place we've already upgraded the coal transport infrastructure, the underground belt systems and surface handling facilities and now we're upgrading the entire longwall," Cameron said.

"At Springvale we've recently moved into the first of our larger blocks and also widened the blocks so Springvale longwall's production is also increasing dramatically. Together the Angus Place / Springvale complex will be producing over 6 million tonnes per annum for both domestic and export."