Asian immigrants help to reshape Silicon Valley as entrepreneurs.

A year after arriving in the U.S. in 1985, Sherman Tuan quit his job with Taiwan_s Acer Corp., bought a used Chevrolet van and spent six months touring the country, supporting himself by trading things at flea markets. 13 years later, Mr. Tuan heads his fourth company, AboveNet Communications Inc. of San Jose, Calif., which helps Internet-service providers and large businesses handle Web traffic. AboveNet went public in December, and its shares have more than quadrupled since then, giving the company a stock-market valuation of more than $1 billion. Wednesday, Mr. Tuan agreed to sell the company for $1.5 billion in stock to Metromedia Fiber Network Inc. Taiwan-born Mr. Tuan is just one of the immigrants who have transformed Silicon Valley over the past two decades. Long known for their engineering expertise, these immigrants also are among the region_s most active entrepreneurs, according to a new study. Ethnic Chinese and Indian immigrants run nearly 25% of the high-tech companies started in the Valley since 1980, according to the study by Anna Lee Saxenian, a professor of regional development at the University of California, Berkeley. The 2,775 immigrant-run companies had total sales of $16.8 billion and more than 58,000 employees last year. Ms. Saxenian says those figures likely understate the contributions of immigrant entrepreneurs, because many companies they started are run by native-born Americans. But there_s evidence that the traditional pattern is changing. Chinese and Indian immigrants run 29% of the companies founded between 1995 and 1998, a figure Ms. Saxenian thinks is a more accurate reflection of their influence. "The big change in the 1990s is the recognition of not just the technical, but the managerial capabilities of immigrants," says Ms. Saxenian, author of "Regional Advantage," a well-regarded book about the growth of Silicon Valley.