WASHINGTON — Korean-owned businesses have transformed the intersection of Highways 28 and 29 in Centreville, Va., where Hangul-lettered signs for soft-tofu restaurants, acupuncture clinics and karaoke rooms mark this as one of several Korean commercial hubs emerging around the region.

Yet what happened behind the signs is evidence of an even deeper economic transformation. A shopping center at the junction is not just filled by small Korean businesses, but is owned by grocery-store-owner-turned-developer David Min Sik Kang. It is managed by a Korean company. Korean-American bankers like Michael Kim at Nara Bank are helping finance some of the businesses; Korean-American brokers and lawyers are drafting the contracts and helping set up operations.

Part of a four-decade evolution, ethnic Korean investors and entrepreneurs in the area are expanding beyond corner groceries and liquor stores to supermarket chains, golf courses and commercial property development. In the process, a professional infrastructure also has emerged to support those new businesses with financing, legal expertise and other services that were harder to obtain for earlier immigrant business owners.

It's a process that has changed over time. Earlier immigrants from South Korea often came from professional backgrounds but, unable to transfer their licenses and degrees, put their energy into developing small businesses. Their children are now emerging as lawyers, pharmacists, teachers and accountants. Immigrants today are leaving behind a South Korean economy that is itself robust. They often arrive with money to invest and, unlike many other immigrant groups, are not under pressure to support extended families in countries that are beleaguered by conflict or economically depressed.

"If things keep moving in this direction, Washington may become like Los Angeles, where the Korean community is self-sufficient with an economic engine of its own," said Young Jae-park, who opened a local office for Los Angeles-based Hanmi Bank last year.

The number of Asian-owned businesses in the Washington area increased 30 percent from 1997 to 2002. Now there are 40,152, part of a surge in entrepreneurship among ethnic and racial minorities that has tracked the growing diversity of the region's population.

Among Koreans, the number of businesses grew 21 percent, to 9,406, the largest among Asian groups. The community has pushed beyond a pattern of settlement in poorer downtown neighborhoods, where small Korean-owned stores sparked tensions between longtime residents and the newcomers, and moved outside long-standing communities like "Koreatown" of Annandale, Va. Though Korean businesses are still a small portion of the regional economy — 2 percent of all firms — they are reshaping Centreville and other communities including Ellicott City and Wheaton, Md., and Chantilly, Va., making the population more visible across the region as it gains economic momentum.

"What we are seeing is a maturation of the Korean community" said Dae Young-kim, a professor of sociology and Asian-American studies at the University of Maryland at College Park. "It is more diverse with more and more people moving out of traditional urban ethnic enclaves and increasingly beyond traditional small businesses."

As the Washington area continues to attract more Korean businesses, the community has developed a stronger economic identity, where more powerful leaders have emerged and newcomers are greeted with more business opportunities.

That's what brought Hanmi and three other Los Angeles-based Korean-American banks to the Washington region in the past three years. The U.S. subsidiary of Korea's Woori Bank also opened two branches since coming in 2003 and plans to open another branch in Centreville at the end of the year.

While many Korean business owners get financing from mainstream banks or through carry-over notes — where buyers set up financing agreements directly with sellers — the formation of a Korean financial sector has expanded the options, particularly for new immigrants without a history of credit or assets.

"We understand the situation of Korean immigrants, who often aren't the kind of clients other banks will look at," Young said. "To us, they are the perfect client because they will do everything they can to make their business succeed."

To be sure, the loans are small compared with the large financial institutions. Yet the banks are expanding, with more staff and plans to open full retail branches.