Stocks were set for a weak open on Thursday after data showed first-time claims for jobless benefits rose unexpectedly, underscoring ahead of Friday's key jobs report the hurdles facing a recovery in the labor market.

After treading water, futures fell after data showed initial claims rose to 479,000 last week, defying analysts' expectations for a slight decline.

The report came a day before the closely watched monthly nonfarm payrolls report, with economists forecasting a drop of 65,000 in July as U.S. Census Bureau jobs dried up. Private employers are expected to add 90,000 jobs. Better-than-expected data out of the private sector on Wednesday had helped temper some jitters about the job market.

Investors have been anxious to see improvement in the labor market with high unemployment remaining a major roadblock to a sustainable recovery. Worries that the pace of the recovery is slowing have also plagued investors.

After (the ADP report), this is a big disappointment, and that doesn't bode well for tomorrow, said Dan Cook, senior market analyst at IG Markets in Chicago.

Unemployment is very much the focus, and it's impacting how we look at the retail sales data as well.

Disappointing July sales figures from several retailers also put pressure on the market, with seven of the 11 retailers that reported so far missing expectations, according to Thomson Reuters data. Among the laggards, Hot Topic Inc lost 4.2 percent to $5.04 in premarket trade, while The Buckle fell 6.3 percent to $25.49.

S&P 500 futures fell 7.2 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 dropped 32 points, and Nasdaq 100 futures fell 6.25 points.

BP Plc's U.S.-listed shares rose 2.6 percent to $40.40 in premarket trade on hopes its oil well in the Gulf of Mexico will soon be permanently sealed.

Insurer Cigna Corp reported a far higher-than-expected quarterly profit and raised its full-year forecast. Cigna was up 3.2 percent at $33.17.

Nonetheless, a positive technical picture could stem declines after the S&P 500 held above its 200-day moving average for a third day in a row on Wednesday.

Stocks rose in thin trade on Wednesday, lifted by retailers' earnings and better-than-expected economic data.

(Additional reporting by Ryan Vlastelica; Editing by Padraic Cassidy)