NEW YORK (AP) -- Wall Street suffered one of its worst losses of 2007 Thursday, leading a global stock market plunge as investors succumbed to months of worry about the mortgage and corporate lending markets. The Dow Jones industrials closed down more than 310 points after earlier skidding nearly 450.

Investors who had been able for months to largely shrug off discomfort about subprime mortgage problems and a more difficult environment for corporate borrowing finally decided it was time to sell after the Commerce Department issued another disappointing home sales report.

Feeding the plunge were concerns that higher corporate borrowing costs will curb the rapid pace of takeovers that had driven stocks higher this year. Investors also feared the sluggish environment for home sales and continued defaults in subprime loans would spur debt defaults and weigh on corporate earnings.

While stocks plummeted, investors poured money into the safe haven of the bond market. The soaring price of Treasurys pulled

WASHINGTON (AP) -- Sales of new homes tumbled in June by the largest amount in five months, provoking new worries on Wall Street about how much the prolonged housing slump will hurt the overall economy.

The Commerce Department reported Thursday that sales of new single-family homes dropped by 6.6 percent last month to a seasonally adjusted annual rate of 834,000 units. The decline was more than triple what had been expected and was the largest percentage drop since sales fell by 12.7 percent in January.

The fall in new home sales was the latest piece of evidence this week of housing's troubles. Sales in the much larger existing home market also fell in June, dropping by 3.8 percent to an annual rate of 5.75 million units, the slowest pace in nearly five years. Also this week, Countrywide Financial, one of the largest mortgage lenders, reported a sharp drop in second-quarter profits. The company said rising default rates were spreading from subprime to more conventional mortgages.

All these developments unnerved Wall Street, where concern is growing that the problems with subprime mortgages could mean

HOUSTON (AP) -- Don't let Exxon Mobil Corp.'s 1 percent drop in second-quarter profit fool you. It was still the fourth-best quarterly result for an American company -- ever. And analysts say the company's massive global footprint points to more big quarters.

The world's largest publicly traded oil company said Thursday lower natural gas prices and a drop in production hurt results for the April-June period, contributing to a rare miss of Wall Street expectations.

But Exxon Mobil's net income of $10.26 billion was still eyepopping and off only slightly from the $10.36 billion it earned in the second quarter of 2006 -- the third-best U.S. quarterly result. It already holds the record for the No. 1 quarterly and annual profits.

On a per-share basis, Irving, Texas-based Exxon Mobil reported earnings of $1.83 a share in the most-recent quarter, up from $1.72 from a year ago, reflecting about 7 percent fewer shares on the market from a year ago because of an ongoing stock buyback