NEW YORK - The problems that have weighed on investors all summer - European debt and fear of a new recession in the United States - hammered the stock market Friday. The Dow Jones industrial average fell more than 300 points.

The plunge erased the week's gains for stocks and sent the Dow below 11,000. It had not closed below that level since Aug 22, after several weeks of extraordinary volatility.

The European Central Bank said a top official, Juergen Stark, was resigning almost three years before the end of his term in 2014, revealing deep disagreement over how to solve economic problems in Europe.

Traders fear that one of the continent's heavily indebted economies could default, an event that would ripple through the global banking system and make it difficult for other European countries to borrow money.

Such an outcome could tip the world economy back into recession. In the US, economic growth is already slowing, and unemployment is stuck above 9 percent.

Friday was also the first chance for the markets to react after President Barack Obama presented Congress and the nation a $447 billion jobs program. It is not clear to traders that the plan will get through a bitterly divided Congress.

The Dow finished down 304 points, or 2.7 percent, its steepest drop in more than three weeks. It closed at 10,992. The average approached a 400-point drop at some points in the afternoon.

"Markets always vacillate between fear and greed, and today we're coming down pretty much all on the fear side," said Kim Caughey Forrest, equity research analyst at Fort Pitt Capital Group.

The Standard & Poor's 500 closed down 32, or 2.7 percent, at 1,154. The Nasdaq composite is down 61, or 2.4 percent, at 2,468. All three indexes finished down for the week.

Investors drove the yield on the 10-year Treasury note to 1.92 percent, its lowest since the Federal Reserve Bank of St Louis began keeping daily records in 1962. The yield was 1.99 percent a day earlier.

Wall Street traders have poured money into US government debt all summer, driving the price up and the yield, which moves in the opposite direction, down.

Even after Congress narrowly met a deadline for raising the limit on how much the government can borrow, barely avoiding a default for the country, investors think US government can be counted on to pay its bills.

Word of the resignation of Stark, the top economist at the ECB, came shortly after US markets opened. He was an advocate for higher interest rates, and published reports said he left because he opposed the bank's extensive purchases of debt issued by European countries.