NEW YORK (CNN/Money) - Hurricane Katrina wrought untold amounts of damage. But nationally, what is considered to be the largest natural disaster in U.S. history may not devastate or significantly alter companies' hiring plans in the fourth quarter.

In a survey of nearly 16,000 companies completed just before Katrina struck, global staffing firm Manpower found that 29 percent of employers said they expected to add to their payrolls in the fourth quarter, while 57 percent reported no intention of changing their payrolls. Only 8 percent said they planned to reduce staff levels.

That's on par with the hiring outlook from the seven previous quarters.

As a result of lessons learned from the economic downturn in the past few years, "employers have achieved an unprecedented level of precision in managing their workforce. That is why we continue to see such a high consistency in our survey results," said Manpower chairman and CEO Jeff Joerres.

Nevertheless, in the areas affected, Katrina is "clearly going to have a dramatic effect on the number of unemployed and the number of companies that can hire," Joerres said. But, he added, "We see this as isolated."

In fact, there may be an increased hiring demand among those companies that pick up work from the businesses and industries that had a large presence in the affected areas.

Tourism and conventions – staples of New Orleans' economy – will go elsewhere in the near term. That means more business for convention centers, hotels and restaurants in other cities, said John Challenger, CEO of outplacement firm Challenger, Gray & Christmas.

Likewise, since New Orleans serves as a major port and warehouse for shippers, companies that specialize in warehousing or make materials for warehousing will likely see an increase in business and perhaps greater need for workers, Joerres said.

Moreover, the rebuilding effort is likely to benefit construction firms and furniture makers (including office furniture makers), among others, he added.

In the immediate wake of Katrina, economists predicted that the disaster would curb GDP growth this year, and the job loss resulting from the hurricane would erase at least three months of employment gains.

"The question for the economy at large is to what extent will it absorb these people and these businesses," Challenger said.

To that end, the Department of Labor on Monday announced that it was creating the Katrina Recovery Job Connection, a Web site that will work to connect employers seeking help and those made unemployed by Katrina.

Manpower has said that it has immediate openings for temporary and permanent positions throughout the country and along the Gulf coast. Joerres noted that clients in Shreveport, La., for example, have been seeking temps to help not only with clean-up efforts but to man call centers and fill other jobs to meet general business demands.

And, the company noted in a release last week, many of its 75,000 clients have partnered with Manpower to provide opportunities for Katrina survivors.

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