NEW YORK (AFP) - US stocks opened flat on Thursday, but sinking shares in the retail giant Wal-Mart Stores weighed on the Dow Jones Industrial Average.

Five minutes into trade, the Dow was up less than 0.1 per cent at 18,885.26 while the broader S&P 500 rose 0.2 per cent to 2,181.02. The Nasdaq also gained 0.2 per cent at 5,302.38.

The weak open followed comments by US Federal Reserve Chair Janet Yellen, who said an increase in US interest rates could occur "relatively soon", supporting investor expectations that a hike is likely in December.

Official economic data released Thursday also pointed to relative health in the US economy, with the consumer price index showing a strong monthly rise in inflation and home construction rebounding in October. New claims for unemployment insurance also hit a 43-year low.

Wal-Mart Stores saw shares fall 2.9 per cent after announcing third-quarter revenues had risen 0.7 per cent, below analyst expectations.

Other major retailers were also either down or flat, with Whole Foods losing 2 per cent, Costco off 1.7 per cent and Target up less than 0.1 per cent.