(Updates with U.S. late-day action)
By Neil Shah
NEW YORK, Jan 17 (Reuters) - World stockmarkets slid for a third straight day on Thursday as more weak U.S. economic data fanned fears of a recession, and bond prices jumped after Federal Reserve Chairman Bernanke boosted expectations for an aggressive interest rate cut in his testimony to Congress.
The benchmark U.S. Standard & Poor's 500 Index fell almost 3.0 percent, bringing the decline for the year so far 9.2 percent.
Wall Street was hit by Merrill Lynch & Co Inc <MER.N>, the world's largest brokerage, announcing a nearly $10 billion quarterly loss, with writedowns of over $16 billion. Investors have been acutely worried about the continuing impact of the subprime mortgage crisis on the financial sector and the availability of credit.
Showing the downturn spreading to the manufacturing sector, a Philadelphia Federal Reserve Bank survey said factory activity in the U.S. mid-Atlantic region contracted dramatically in early January. That report also pushed European shares into negative territory after a rollercoaster session.
"Philly Fed was lower-than-expected. It kind of shocked the market," said Cleveland Rueckert at Birinyi Associates Inc. in Stamford, Connecticut,
In testimony before the U.S. House of Representatives' Budget Committee, Fed chief Bernanke repeated his recent downbeat economic views, giving another signal that he will likely push through a hefty half-percentage point rate cut at the central bank policy committee meet at month's end.
Investors were also hit with more bad news about the U.S. housing market as a government report showed that groundbreaking on new homes last month slumped to the slowest pace since 1991, while building permits sank to their lowest since 1993.
The Dow Jones industrial average <
> ended down 2.43 percent, at 12,163.44, while the Standard & Poor's 500 Index <.SPX> fell 2.89 percent at 1,347.66, and the Nasdaq Composite Index < > was off 1.89 percent at 2,367.04.Concerns about the U.S. economy slipping into recession also pushed oil prices down nearly a dollar to about $90 a barrel.
U.S. TREASURY BONDS BENEFIT
The Philadelphia Federal Reserve Bank's data on factory activity boosted prices of U.S. Treasuries, which tend to rise on signs of a softening economy.
The reading "is a fresh reminder that the manufacturing sector continues to struggle -- we are seeing a bid come back into the Treasury market," said Wan Chong Kung, senior fixed-income portfolio manager at First American Funds in Minneapolis.
In the afternoon, the two-year Treasury note's yield dipped below 2.4268 percent to the lowest level since September 2004.
"When the head of a central bank says there may be a need for additional action, the writing is already on the wall," said David Watt, senior currency strategist at RBC Capital Markets in Toronto.
Benchmark 10-year notes rose 27/32 in price to yield 3.6377 percent. Two-year notes climbed 4/32 to yield 2.4368 percent.
GLOBAL FEARS
Fears that a U.S. recession may lie ahead has roiled global stock markets in recent weeks.
U.S. blue-chip shares are down about 7.3 percent since the start of the year, while the MSCI's main world stock index is down 7 percent. The index was down 0.89 percent at 369.49 Thursday.
After trading in the black, the pan-European FTSEurofirst 300 index <
> ended down 0.6 percent.By contrast, Japan's benchmark Nikkei average rose 2.1 percent, gaining for the first time in five sessions. It ended the session up 2.1 percent at 13,783.45, and the broader TOPIX index <
> was up 2.2 percent at 1,330.44.(Additional reporting by Jeremy Gaunt and Randy Fabi in London and Caroline Valetkevitch, Kristina Cooke, Nick Olivari, Gertrude Chavez-Dreyfus and Chris Reese in New York) (Reporting by Neil Shah. Editing by Richard Satran)