You don't have to pay retail for business-class seats anymore. A growing number of airlines are offering significant discounts on business-class tickets to travelers who book well in advance. In February, Air France introduced a new business-class fare that is about half the normal price: about $4,000 for a round-trip trans-atlantic flight when purchased 30 days in advance, compared with about $8,000 when booked just a week in advance or as much as $11,000 at the last minute. About the same time, British Airways restructured its business-class fares from a single flat rate — typically $10,000 between New York and London — to a new tiered-fare system that offers deep discounts to travelers who book early. Lufthansa already offers a similar deal with business-class fares as low as $2,739 for a round-trip ticket between New York and Frankfurt booked more than 50 days ahead, compared with about $8,000 normally. The deals come as demand for those cushy seats in the front of the plane is sagging. Premium travel, highly sensitive to the economic cycle, has been slowing since its peak last August, according to the International Air Transport Association. In January, sales of business- and first-class tickets barely grew, rising just 0.4 percent compared with the month last year. And with the increasingly grim outlook for the United States economy and financial markets, business travel could continue to slow. The new deals are aimed squarely at leisure travelers who have the flexibility to book well in advance, with the deepest discounts offered to customers booking as many as 60 days out. To make sure they don't cannibalize their lucrative business clients, these fares come with certain requirements like Saturday-night stayovers. And unlike the so-called walk-up fares business travelers tend to buy, discount business-class tickets are almost always nonrefundable and come with hefty fees upward of $400 for any changes. For example, Air France is offering business-class tickets from Washington to Barcelona starting at $3,362 round trip, compared with about $5,100. But to get the lower fare, customers must book at least 30 days in advance, stay a minimum of seven days and connect through Charles de Gaulle International Airport in Paris. Travelers who can book as many as 60 days in advance can score a ticket for as much as 60 percent off. British Airways' new fare structure offers tiered business-class markdowns, with the best deals going to travelers who book the furthest in advance. Travelers who buy 42 days in advance and stay over a Saturday night pay about $3,000 round trip for business-class seats between New York and London, compared with roughly $3,200 for tickets bought 14 days in advance with a Saturday night stay. By contrast, a seven-day advance purchase fare is about $8,000 with no other restrictions. And walk-up fares can be $10,200. Most of these so-called structured discounts are being introduced in the highly competitive trans-Atlantic market, where United States carriers, faced with stiff competition from low-cost airlines at home, have been adding flights at a dizzying pace. Major carriers are also facing increasing competition from new, all-business-class airlines like Eos and Silverjet, which have been offering New York to London business-class service for considerably less than the bigger carriers. But travelers are finding other ways to get deals on premium seats to other regions. American Express Platinum cardholders, for example, who buy a first- or business-class ticket at full price to nearly any destination through their Platinum Travel Service, get a free companion ticket. And many airlines now offer so-called y-up or q-up fares — those coveted first- or business-class seats that sell at coach prices. ON top of these deals, a growing number of airlines have been rolling out periodic business-class fire sales to Europe. Right now, for instance, Continental is offering a summer sale of business-class seats from its Newark hub for as low as $1,598 round trip to Belfast, $1,798 to London and $1,998 to Amsterdam. Similarly, British Airways has been running a business-class sale with round-trip fares starting at $2,056 between New York and London. Today is the last day to purchase the discounted tickets for travel in June and August. And Swiss International Air Lines is offering July and August specials from Boston to Rome for $2,914 round trip, compared with about $8,800 normally, and $2,903 from New York to Venice compared with $8,600. Tickets must be purchased by the end of April. Not long ago, discounts on business class seats were unheard of. “You had to buy rack rate and that was it,” said John Lampl, a spokesman for British Airways. “Business fares were kind of sacred.” Now, however, such sales are becoming as routine as post-holiday specials at the mall. And just as savvy shoppers never pay full price for designer duds, thrifty travelers are increasingly nabbing discount premium seats. “People wait for it,” said Joe Brancatelli, publisher of the subscription travel Web site JoeSentMe.com, where members receive regular e-mail alerts about such sales. One of his subscribers, Bob Thompson, a broadcast lawyer from McLean, Va., recently snapped up two business-class tickets from Newark to Milan for a summer vacation with his wife, Petra. Total cost including taxes: $4,150. Staying on top of the sales, said Mr. Thompson, “means you don't have to pay the sucker walk-up business-class fare.” Last year, he got four business-class seats for $1,500 each to London during Christmas, and four business-class tickets for $1,500 each to vacation in Brussels last summer. Both flights were from Newark. “Had I wanted to buy a coach ticket to Brussels, it was going to be $1,100,” he said. “That's a difference of only $300 each way.” - NYT __