(BusinessSpectator) - Treasury Wine Estates says its performance over the first half of the 2015 financial year is on plan and ahead of the prior year at the same stage.

The Australian wine maker and distributor told shareholders at its annual general meeting today that the performance was driven by changes in its Penfolds release dates to October each year, and a result of actions to "reset, fix and invest" in the business.

Chief executive Michael Clarke said Treasury had restructured its distribution model and agreements in China, Taiwan and Korea, which will allow the group to step-change its growth in North Asia in future quarters.

The group in June announced a 50 per cent increase in consumer marketing, funded by a $35 million cut in overhead expenses. Mr Clarke said the cost reduction was largely completed.

Treasury Wine made a loss of $101 million in 2013/14, amid senior management changes, company restructuring and the costly destruction of hundreds of thousands of cases of excess wine.

Mr Clarke was appointed in February and he has since set about overhauling the company with a massive marketing push and focus on high-end markets.

Australia remains Treasury Wine's home market, but the US and Asia, particularly North Asia, were the growth markets, he said on Tuesday.

The US was also a significant growth opportunity and having scale there was critical, Mr Clarke said.

Therefore Treasury Wine would maintain its portfolio of cheaper commercial wines in the US, until its prestige and luxury wines there grew to a significant size.

Mr Clarke said the company did not necessarily need more luxury brands in the US, but an increased supply of quality wine could "step change" Treasury Wine's US portfolio.

Treasury Wine will announce its first half results in February.