New Southcorp owner Foster's says it will revitalise its leading Rosemount brand, though doing so may take a couple of years.

Only two years ago, under Southcorp's ownership, Rosemount had 5% of the Australian market. This has since slipped to under 3%.

Foster's Wine Estates senior executive Randolph Bowen warned at a company conference that there were no instant fixes.

Bowen added that Southcorp had lost priority and focus on Rosemount.