As if corporations needed another headwind in 2009, it now appears that the cost of business travel will increase substantially next year.

Travel managers at large companies are forecasting a 5 to 8 percent increase in business travel costs in 2009, according to a new survey released by the National Business Travel Association. Almost every major travel expense—airfares, hotels and car rentals—is expected to increase on some level next year, with providers likely to pursue heftier pricing because of the pressures on their own businesses.

“In a more normal environment, this wouldn’t necessarily be a major concern,” said Kevin Maguire, president of the association. “This is anything but a normal environment.”

More companies will be looking to tighten up their travel and entertainment budgets next year, Maguire noted, and will have to find new ways to confront these increasing costs without eliminating essential business trips.

The most significant area of expense, he noted, will be airfare. Roughly 80 percent of travel managers polled by the National Business Travel Association said they expected to spend more next year. The average cost of a round-trip domestic business flight in coach is expected to rise to $354 in 2009, an increase of roughly 10 percent from this year.

Maguire added that the wide range of fees that airlines now charge passengers for baggage, meals or beverages makes it more of a challenge for businesses to accurately predict airfare costs.

Hotel rates, meanwhile, are expected to go up by 1 to 4 percent and could hit an average of $130 per room. Car rentals will cost 1 to 3 percent more next year, and could run an average of $44 per rental, according to the National Business Travel Association survey.

Filed by Mark Bruno of Financial Week, a sister publication of Workforce Management. To comment, e-mail editors@workforce com.

Workforce Management’s online news feed is now available via Twitter.