Pop into a McDonald's in Tokyo's business district on any weekday and you'll find a crowd of salaried workers.

Thanks to discount campaigns, what was once considered the turf of kids and young people has become a restaurant for all ages, making the selling strategy something many of the country's fast food chains have had to adopt -- whether they like it or not.

In February, McDonald's Co. (Japan) Ltd. began offering special 50 percent discounts, slashing prices for ham- and cheeseburgers to 65 yen and 80 yen, respectively, Monday through Friday, with the regular price maintained on weekends.

The new price strategy has created a new breed of customer, said Kenji Kaniya, manager at McDonald's public relations department. Most conspicuously, he said, middle-aged office workers have begun coming for lunch.

"Before the campaign, we used to sell about 25,000 hamburgers and cheeseburgers a day," Kaniya said. "The number surged to eight times that level at one point, and now it has stabilized at a level about five times the original."

As the nation's top fast-food firm, McDonald's is a marketing trendsetter, and a number of its competitors have been forced to follow its lead, even if it cramps profits.

Starting Aug. 21, Lotteria, the third-largest hamburger chain operator in Japan, will also launch a half-price campaign, selling hamburgers for 65 yen.

"I think prices will be lowered further, and many food service operators will be forced to drop out," said Hiroshi Hoshino, a securities analyst at Nomura Securities Co.'s Financial Research Center.

And such drastic price slashing is moving beyond hamburger chains.

Skylark Co., the nation's largest restaurant chain operator, last month opened Club Lark Hills in Kodaira, western Tokyo. An experimental restaurant, it offers low-priced dishes such as boxed lunches of sushi and Chinese noodles for 380 yen each, a hamburger steak for 290 yen and a variety of rice balls for 65 yen each.

Makoto Suzuki, a public relations official for Skylark, acknowledged that the rice balls were consciously priced in line with a McDonald's hamburger.

Likewise, Kobe Lump Tei Inc., a beef-bowl shop chain operator, has been offering discounts since July 1, selling takeout beef bowls for 290 yen instead of the regular 400 yen.

While acknowledging that McDonald's has been fueling the discount trend, industry watchers point out that price competition is nothing new.

In the prolonged economic slump that followed the burst of the bubble in 1991, Japanese consumers have grown sensitive about prices, forcing food service chains to lower them, they said.

According to the Japan Food Service Association, an industry group of major food service firms, the average amount paid per customer suffered two consecutive years of decline, down 1.6 percent in 1998 then an additional 1.7 percent in 1999.

Both Kaniya of McDonald's and Suzuki of Skylark say that the turning point for the food service industry came around 1993.

Around that time, McDonald's suffered a rare decline in sales, prompting the company to look into consumers' desires.

Having concluded that customers were dissatisfied with prices, McDonald's embarked on substantial cost-reduction efforts. One strategy it adopted was so-called global purchasing, a groupwide initiative to purchase ingredients for all McDonald's shops worldwide from one supplier offering the best prices.

McDonald's Japan also began to set up a number of "satellite shops" -- small in size and cheap to operate -- close to full-scale parent shops in busy downtown areas.

Such shops' break-even point in monthly sales is between 4 million yen and 5 million yen, about 10 million yen less than a full-fledged shop, Kaniya said, citing the training of satellite shop employees at parent shops as one cost-cutting factor.

Between 270 and 280 of the estimated 400 shops opened by McDonald's in Japan every year are satellite shops, he said.

Skylark tried a similar strategy. From 1993 to 1994, it launched about 500 low-price restaurants under the brand name Gusto.

The move, according to Suzuki, was in response to drastic changes in customer preferences following the burst of the economic bubble.

Since that time, he said, customers' tastes have become polarized, with a cheap menu preferred at one end and good food and a nice atmosphere, at a cost, of course, on the other.

"Those falling in between are suffering the most now," Suzuki said.

Skylark is now replacing its traditional-style restaurants with Gusto, a Western-style food chain, and Bamiyan Chinese restaurants.

Due to their comparatively low prices, customers spend an average of 820 yen per visit at Gusto and 930 yen at Bamiyan. Still, the two chains enjoy better earnings rates than Skylark shops do thanks to lower operating costs, Suzuki said.

The key to affording cheaper prices is reducing staff costs.

At Gusto restaurants, waiters take orders only when customers ring a bell, and at Bamiyan restaurants, soft drinks are provided through all-you-can-drink self-service machines.

Thus, a Gusto restaurant would have four to five floor staffers, when seven to eight would be required at a Skylark restaurant.

The right equipment is also important.

"We have changed cooking equipment so that even a part-timer can grill steaks or hamburgers," Suzuki said.

Hoshino of Nomura Securities said low-productivity equipment and heavy dependence on labor are mainly to blame for keeping overall prices at Japanese restaurants and diners relatively high.

According to Nomura Securities, the consumer price index rose by about 40 percent from 1980 to late 1999, but the price index for food services stayed at a level about 10 points higher than that.

"Now pressures are working to lower the prices of food services," Hoshino said, arguing that large-scale operators with cost-cutting strategies have more room to offer lower prices than their inefficient rivals.