LONDON — Concerns over a slowdown in the world’s biggest economies hit world markets today, with weak indicators out of China and Europe’s financial turmoil unsettling investors ahead of a crucial U.S. jobs report.

A survey of China’s manufacturing activity, the purchasing managers’ index, fell to 50.4 points in May, suggesting the sector, which has driven growth in the world’s second-largest economy for years, is stagnant. Any figure above 50 means the sector is expanding and below that, it is contracting.

“The (Chinese) data is so bad, and so clearly points to slowdown of growth momentum, that it will likely help convince policy makers that the economy needs more stimulus,” Dariusz Kowalczyk, senior economist at Credit Agricole CIB in Hong Kong, said in an email.

Britain’s FTSE 100 fell 0.6 percent to 5,286.58 while Germany’s DAX plunged 2.1 percent to 6,131.79 and France’s CAC-40 lost 1.3 percent to 2,979.35.

Asian indexes closed lower, with Japan’s Nikkei 225 index down 1.2 percent, and Wall Street was expected to slide on the open. Dow Jones industrial futures fell 0.7 percent to 12,300 and S&P 500 futures lost 1.2 percent at 1,293.30.

The gloomy data further darkened the mood among investors, who have been increasingly spooked by the possibility that the 17-country eurozone might break up.

The head of the European Central Bank drove home those concerns Thursday, when he told European Union leaders that the euro currency union is unsustainable in its current form.

The euro has fallen nearly 7 percent in May and was down another 0.3 percent Friday to hit a new two-year low of $1.2326.

The likelihood of Greece leaving the euro grew in early May, when parties opposed to the terms of the country’s financial rescue won at the polls. New elections are planned for next month.

This week, Spain became the new focus of the crisis after its borrowing rates soared to nearly 7 percent, a level that is considered unsustainable for a country to continue funding itself by selling bonds to investors. Greece, Portugal and Ireland were forced to ask for financial aid after their rates went over 7 percent.

The economic outlook is more likely to worsen than improve. According to the latest official figures, unemployment in the eurozone remained at a record high of 11 percent in April, though it worsened in struggling countries like Spain, Portugal and Greece. Youth unemployment in Spain hit a staggering 51.5 percent.

Against that backdrop, investors will hope that U.S. economic data can show signs of progress. The monthly employment report, one of the most important indicators of the health of the world’s largest economy, is due later in the day.

Economists expect it to say that employers added 158,000 jobs. That would be better than in the past two months but far below the winter’s pace of 252,000 jobs per month. They also expect no change in the unemployment rate, which was 8.1 percent in April.

“Unemployment and nonfarm payroll will be key,” said Jackson Wong, vice president of Tanrich Securities in Hong Kong.

Earlier in Asia, Japan’s Nikkei 225 index closed 1.2 percent lower at 8,440.25 and South Korea’s Kospi dropped 0.5 percent to 1,835.51.

Australia’s S&P/ASX 200 index lost 0.3 percent to 4,063.90. Benchmarks in Singapore, Taiwan, Indonesia, India and New Zealand were also lower.

Hong Kong’s Hang Seng ended 0.4 percent lower at 18,558.34 after briefly posting gains amid hopes for stimulus measures by the Chinese government. Mainland Chinese shares were flat.

Benchmark oil for July delivery was down $1.46 to $85.07 per barrel in electronic trading on the New York Mercantile Exchange. The contract fell $1.29 to settle at $86.53 in New York on Thursday.

The dollar rose to 78.35 yen from 78.33 yen late Thursday in New York.

Pamela Sampson in Bangkok contributed to this article.