Cary will spend $6.1 million to add 3,000 seats to the Triangle's largest soccer stadium by next fall, with Raleigh and Wake County expected to reimburse half that cost by 2020. The stadium already is home to a professional soccer team, but town leaders want to claim another valuable market: amateur and collegiate sports.

"We've been calling ourselves an amateur sports mecca," Mayor Harold Weinbrecht said last week.

As the soccer park upgrade begins, the town also has multimillion-dollar plans for its USA Baseball National Training Complex and the Cary Tennis Park, and prepares for international table tennis matches.

Councilwoman Jennifer Robinson said amateur and collegiate sports are a reliable niche for the town of about 140,000 residents. Other municipalities and schools, however, have the same idea, and Cary hopes to hang on to the visibility and tourism dollars that sports brings the town.

"The sports-event industry is more competitive now than ever, as more and more cities of all sizes realize the benefits of hosting sporting events, mainly on economic development," said Scott Dupree, vice president for sports marketing at the Greater Raleigh Convention & Visitors Bureau.

Cary hosted the men's or women's college soccer championships from 2003 to 2010 but lost out this year to Hoover, Ala., and Kennesaw State University in Georgia.

This weekend's women's soccer finals at Kennesaw State are the first in Atlanta since 1968. The reason: Kennesaw State, 20 miles north of Atlanta, "has got more skyboxes than we've got, the technology is a lot newer than what we've got," said William Davis, Cary's athletics manager. "It's very attractive to organizations."

The National College Athletic Association told Cary it would need better facilities to again host the soccer championships. But even as the town committed to the project in October, the University of San Diego landed the 2012 women's championship. The San Diego Union-Tribune reported the city's warmer weather swayed the selection committee, despite its stadium's smaller capacity and poorer field conditions.

Cary still hopes for the 2012 men's championship and both the men's and women's finals for 2013, with the NCAA's decision expected early next year. The town's expanded stadium also could host international soccer games and Major League Soccer exhibitions with its home team, the RailHawks, Davis said.

The stadium runs an annual deficit of hundreds of thousands of dollars. Its true benefit, town leaders and staff say, is the waves of sports fans who might pay for a restaurant or hotel room on their way to a match. Cary staff cite a report that estimates the NCAA championships have generated $12 million in business for the region since 2005.

WakeMed Soccer Park, off East Chatham Street, has eight fields and cross-country trails that host local and regional meets. Its operations will go on largely uninterrupted during the upgrades.

Cary already has rough plans for further expansion at the soccer park, and Raleigh and Wake County have pledged up to $10 million of hotel occupancy tax money to match the town's investments in sports facilities. The town eventually could spend several million dollars more on a video board, new buildings, thousands of new seats and field improvements at the soccer stadium and for expansions of its baseball and tennis centers.

The town can gauge the economic benefits by surveying visitors about their spending, said Coyte Cooper, an associate professor of sport administration at the University of North Carolina. But any influx of tourism dollars may slow as other cities build new stadiums and arenas, complicating forecasts, he said.

"In 10 years, there's new facilities across the way," Cooper said. "How do you keep up with them?"