Same-store food and liquor sales of Woolworths increased to 2.0 per cent during the third quarter, propelling the retailer to trim down its sales forecast for this year.

Woolworths, one of Australia's top supermarket chain, slowed down its sales forecast for 3 years to six per cent from an earlier forecast, but supports its net profit growth guidance of eight to 11 per cent.

"Consumer spending has tightened in the quarter, reflecting consumer concerns about further interest rate hikes and higher petrol prices than last year," Woolworths chief executive Michael Luscombe said.

It was reported earlier that Woolworth shares slumped down to 46 cents or 1.7 per cent to $26.45, while the general market upped its shares to 0.6 per cent.

Same-store food and liquor sale downgraded below the growth rates during the previous quarters. Sales showed a rise of 3.8 per cent in the second quarter while the first quarter sales were above 5.8 per cent.

Analysts have previously predicted a sales growth of 3.0 per cent on same-store food and liquor.

Woolworth's overall sales for the third quarter rose to 3.8 per cent to $11.04 billion. This excludes petrol.

Meanwhile, its discount chain Big W declined to 3.7 per cent in sales during the third quarter due to the withdrawal of the government stimulus and a series of interest rate increase.

Westfarmer, a rival company of Woolworths, declared its same-store food and liquor sales growth to 3.8 per cent at its Coles supermarkets last week.

Woolworths' shares fell to 3.9 per cent this year.