The new Web site, called WorldAgent Direct, is designed to relieve travel agents' complaints that they can't offer customers the same low fares that Northwest does to people who buy directly from its public Web site, nwa.com.

The site is similar to one announced last week by American Airlines. But travel agents criticized the American site, called EveryFare, because of fees the airline imposed for using it. Northwest said it won't charge travel agents to use its new site, which begins operation on Oct. 22.

Travel agents can use the public Web sites of airlines to buy tickets for customers, but they rarely do because the sites don't help them perform accounting and other functions as do the more sophisticated computer reservation systems they've used for years.

By offering the same services, including accounting and billing, Northwest's new Web site for travel agents may start to reduce agents' reliance on the existing reservation systems, which both agents and airlines pay to use.

Travel agents for several years have complained about the ultra-low fares airlines offer to consumers who book directly with them via the Web. The acrimony grew this spring when most airlines stopped paying commissions to travel agents, leading to congressional hearings on the tug-of-war between airlines and travel agents.

The Web's emergence in the mid-1990s increased the number of people who buy tickets directly from airlines, but travel agents still sell about three of every four airline tickets. Shifting more agents to Web-based booking is yet another way for airlines to lower costs.

For Northwest, the average ticket sells for about $300 and about $14 of that goes to the fees imposed by the operators of computer reservation systems. It is a co-owner of one of those systems, WorldSpan, with Delta Air Lines and American. But its new Web site for travel agents will be run from its internal computers, not WorldSpan.

"It's hard to predict exactly how the economic model will play out," said Fay Beauchine, vice president of sales and customer relations at Northwest. "What is known is airlines need to reduce their distribution costs. This is one way to do it."

The airline is holding a sweepstakes contest to get agents to try the system and will periodically offer special fares to them through it.

After American's system last week left travel agents unimpressed, Richard Copeland, president of the American Society of Travel Agents, expressed wariness about Northwest's new system. But he said, "The Northwest plan needs further scrutiny."