Tysons Corner Center is opening a 362,000-square-foot expansion today with a 16-screen movie theater, five restaurants and 24 new retail stores, many of them designed to appeal to teenage shoppers.

Owner Macerich Co., a California-based real estate investment trust with large West Coast malls in its portfolio, said the focus on entertainment and youth shores up weaknesses in the retail mix of the 37-year-old shopping center.

"Teen retail is really big right now," said Eric A. Kulczycky, the mall's marketing manager, and with too little of it at Tysons, the mall has expanded a space once occupied by cost-conscious JCPenney and filled it with Urban Outfitters and Esprit, among others.

The latest retail development trends mimic downtown shopping districts with open-air town centers, a dense concentration of stores emptying onto sidewalks and restaurants featuring outdoor dining. But Tysons has remained dominant as a one-stop, weatherproof monolith surrounded by parking garages -- and a parking lot for 1,675 cars adjoins the mall's expansion.

Developers and civic leaders have been arguing for transforming the entire Tysons Corner area into a more pedestrian-friendly space that resembles a downtown, but Macerich executives said that will be part of the next phase of development.

So far, thinking big and bulky has paid off. Tysons' sales per square foot, an industry benchmark, average $630, according to its owners. The national average of sales per square foot, according to the International Council of Shopping Centers, is $366.

"They have a wonderful tenant mix," said Gayle Spurr, director of marketing for Springfield Mall, who estimated that her mall's sales per square foot are slightly above the national average.

The youth-oriented lineup includes Free People, Lucky Brand Jeans and Abercrombie & Fitch Co.'s Hollister Co., which is described in promotional materials as a "laid-back teen destination inspired by the sun-drenched California lifestyle." H Hilfiger, a new retail outlet from the red, white and blue fashion designer, will open sometime this spring, mall executives said. The area's first West Elm furniture store is there, too.

"Retailers understand that you have to pay attention to demographics and look to the future," said Tom Moseman, senior vice president of Envirosell Inc., which studies shopping trends. "You have to lay your tracks now. You're building your future loyalty."

The mall helped transform a cow pasture at Leesburg Pike and Chain Bridge Road into a bustling economic engine. It opened in 1968 as the largest one-level shopping center in the country and doubled in size 20 years later, when a $150 million redesign turned truck tunnels into a second level. The most recent expansion brings the size of the mall to approximately 2.3 million square feet, ranking it as either the fifth or sixth biggest mall in the country.

The expanded entertainment and food options turn the mall into more of a nighttime destination, which mall executives predict will benefit the stores. "It extends the customer's stay, and when they extend their stay they spend more money," said Kathy Hannon, the mall's senior property manager.

The mall's heavy pedestrian traffic makes it a strong draw for retailers.

Barnes & Noble, which opened a two-story, 33,000-square-foot store in the expansion, decided against locating in several sites outside of the mall, including a location across Route 7. The retail space is now occupied by competitor Borders, said David S. Deason, vice president for development at Barnes & Noble.

"I wanted to be in the best possible long-term facility," Deason said.

The bookstore's spot in middle of the restaurant cluster has mutually beneficial opportunities.

"We help them maintain their waits," Deason said. "As opposed to sitting and waiting for a table, come on in and browse."

Mall executives said the new entertainment focus has ancillary benefits, too, for the heavily car-dependent workforce in the area. "Instead of fighting the evening traffic, they can come to the mall, have dinner and go to a movie," said Hannon.

Keeping Tysons Corner Center as a destination shopping venue concerns more than just the mall's owners.

"The mall is the largest single retail source of tax revenue in the county," said Gerald E. Connolly, chairman of the Fairfax County Board of Supervisors. "Making sure it remains competitive is very important to the economic health of the county."

The new section of Tysons Corner Center has a play area, a 16-screen movie theater and five new restaurants that could make it more of a nighttime destination.The new section of the Tysons Corner Center brings the mall to 2.3 million square feet. The mall opened in 1968 and doubled in size 20 years later when it got a $150 million redesign.