The 2010 movie "The Social Network" added to Saverin's fame after it portrayed him as a scorned friend who provided the company's early financing and then was squeezed out. In the film, written by Aaron Sorkin, Saverin was portrayed by Andrew Garfield, who will play Spider-Man in "The Amazing Spider- Man."

Saverin's Investments

Saverin moved to the U.S. in 1992, and became a citizen in 1998, his spokesman said. He has invested in Asian, U.S. and European companies, according to his spokesman.

He plans to keep investing in Brazilian and global companies that have strong interests in entering the Asian markets. "Accordingly, it made the most sense for him to use Singapore as a home base," Goodman said in the statement.

His U.S. holdings include Jumio Inc., an online payments company, and ShopSavvy Inc., a price-comparison service.

Renouncing citizenship is an option chosen by increasing numbers of Americans. A record 1,780 gave up their U.S. passports last year compared with 235 in 2008, according to government records.

Income-tax rates for top U.S. earners will rise to 39.6 percent from 35 percent next year, and rates on capital gains and dividends also are scheduled to rise unless Congress blocks the increases.

'Tax Cost'

"It's a loss for the U.S. to have many well-educated people who actually have a great deal of affection for America make that choice," said Richard Weisman, an attorney at Baker & McKenzie in Hong Kong. "The tax cost, complexity and the traps for the unwary are among the considerations."

Some of the world's largest wealth-management firms have ramped up efforts to fight tax evasion ahead of Washington's implementation of the Foreign Account Tax Compliance Act, known as Fatca, which seeks to prevent tax evasion by Americans with offshore accounts. HSBC Holdings Plc, Deutsche Bank AG, Bank of Singapore Ltd. and DBS Group Holdings Ltd. all say they have turned away business.