Wall Street was set to open lower on Thursday as a weak holiday quarter forecast from retail giant Wal-Mart Stores Inc sparked concerns about consumer spending, threatening to break a six-session rally for the Dow.

The comments from Wal-Mart offset data that showed the number of U.S. workers filing new claims for jobless insurance fell for the second week in a row, with the four-week moving average of claims the lowest in nearly a year.

The (disappointing) outlook from Wal-Mart does not bode well for the overall view on consumer spending, said Tom Schrader, managing director of U.S. equity trading at Stifel Nicolaus Capital Markets in Baltimore.

Wal-Mart shares were up 0.3 percent to $53.20 in premarket trading, reversing earlier losses shortly after the world's largest retailer reported a higher quarterly profit but forecast earnings for the current period that could miss current Wall Street estimates.

S&P 500 futures dipped 2.6 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures fell 18 points, and Nasdaq 100 futures shed 3 points.

Network equipment maker 3Com Corp gained 32 percent to $7.49 in premarket trading after Hewlett-Packard Co said on Wednesday it has agreed to buy 3Com for $2.7 billion.

The U.S. federal budget for October, due at 2 p.m. EST, is expected to show a deficit of $150 billion for the first month in the new budget year, headed toward another $1 trillion-plus tide of red ink.

(Editing by Padraic Cassidy)