Stock futures fell Thursday on persistent investor worries about whether a Greek debt crisis will spread across Europe.

Reports from the Labor Department showing new claims for jobless benefits fell less than expected last week, while productivity jumped more than forecast in the first quarter dragged futures down further.

European markets rose slightly, though investors remain concerned about whether the debt problems will upend a global economic recovery.

The euro is extending its decline against the dollar, a sign that investors are not sure whether a Greek bailout will stem the mounting problems. The euro is at its lowest level against the dollar in 14 months.

Greece is trying to tap a $144 billion aid package from the 15 other countries that use the euro and the International Monetary Fund. The nation needs access to an initial portion of the money by May 19 to cover $11.6 billion in debt payments, or else it will likely default.

Even if Greece gets the money it needs, there are still worries that would be only a temporary fix to a growing debt problem across the continent, and others like Portugal and Spain will eventually need similar rescues.

The European Central Bank kept its benchmark rate at 1 percent. ECB President Jean-Claude Trichet is expected to discuss the growing debt problems later in the day.

Ahead of the opening bell, Dow Jones industrial average futures fell 37, or 0.3 percent, to 10,797. Standard & Poor’s 500 index futures fell 5.10, or 0.4 percent, to 1,158.80, while Nasdaq 100 index futures fell 9.25, or 0.5 percent, to 1,949.25.

The Dow has dropped 284 points over the past two days.

The Labor Department’s weekly report on initial jobless claims showed 444,000 workers applied for unemployment benefits last week. That’s down from a week earlier, but fell short of expectations. Economists polled by Thomson Reuters had forecast claims would drop to 440,000.

It was the third straight weekly drop in new claims. While claims are falling, economists say they have not yet dropped to levels that would indicate consistent job growth. Initial claims would have to dip to around 425,000 to signal employers are adding jobs and the unemployment rate is falling. High unemployment remains one of the key issues facing the U.S. economy as it continues to rebound.

The report comes a day before the Labor Department is expected to report the unemployment rate remained at 9.7 percent in April.

A separate Labor Department report showed first-quarter productivity rose at an annual rate of 3.6 percent, better than the 2.5 percent forecast by economists. The gain, coupled with a drop in labor costs, means companies should be able to maintain strong profit margins. However, it also means that consumers’ incomes continue to be squeezed, which could slow a rebound in spending.

Retailers are also reporting that April sales largely slowed from March’s strong pace, partly because Easter was earlier this year. The spring selling season has been decent, with discounters like Costco Wholesale Corp. doing well last month.

Bond prices fell but moved off their morning lows after the pair of Labor Department reports. The yield on the benchmark 10-year Treasury note, which moves opposite its price, rose to 3.56 percent from 3.54 percent late Wednesday.

Gold and oil both rose.

Overseas, Britain’s FTSE 100 fell 0.1 percent, Germany’s DAX index rose 0.3 percent, and France’s CAC-40 rose 0.6 percent. Japan’s Nikkei stock average, which had been closed the past three days for holidays, fell 3.3 percent.