Australian supermarket operator Coles Myer has posted a near 12% rise in first-quarter sales, helped by a new fuel discount scheme and a major liquor acquisition.

However, comparable sales in the company's food and liquor business, which accounts for 65% of total sales, rose only 1.7%.

Group sales for the 13 weeks to 26 October were up 11.9% to A$7.05bn (US$5.08bn) from $6.30bn a year earlier. Like-for-like sales rose 2.3%.

Coles Myer is in the midst of a fierce battle for market share with rival Woolworths.

"We're starting to close the gap on our major competitor in terms of food and liquor," chief executive John Fletcher was quoted by Reuters as saying.