DuPont, based in Wilmington, Delaware, increased planned job cuts by 1,000 to 5,500 workers, or 6 percent of total staff. Another 1,300 contract workers will also lose their jobs, as previously announced, while the company tries to combat high energy costs, a strong U.S. dollar and weak demand for its products.

``Industries important to many of our customers -- electronics, automotive, textiles and chemicals -- have been particularly affected by the economic downturn,'' said Charles O. Holliday Jr., DuPont chairman and chief executive. ``This has temporarily reduced fundamental demand for our products.''

DuPont posted a net loss of $213 million for the quarter, compared with earnings of $688 million in the period a year ago. Before one-time items, income fell to $432 million, or 41 cents a share, from $949 million, or 90 cents a share a year ago, which was in the range of lowered estimates on Wall Street.

The company warned about its second-quarter profits earlier this month, when analysts were expecting it to earn 53 cents a share. After the warning, analysts polled by Thomson Financial/First Call cut second-quarter forecasts to 35 cents to 45 cents a share, with a mean estimate of 40 cents

Consolidated sales fell to $7.0 billion from $7.9 billion.

The chemicals business appeared even worse in the current quarter, DuPont warned, saying its third quarter ``will be substantially more challenging than the second quarter.''

The company added that earnings for the third quarter would fall from those of the second quarter at least as much as they did between the first and second quarters, when they dropped 24 percent.

Other chemical companies, including Germany's BASF AG and Bayer AG, have also been hard hit this year. Dow Chemical Co., DuPont's top U.S. competitor, is scheduled to report its second-quarter earnings on Thursday, but has already issued a profit warning.