Eduardo Saverin, the billionaire co- founder of Facebook Inc. (FB), renounced his U.S. citizenship before an initial public offering that values the social network at as much as $96 billion, a move that may reduce his tax bill.

Facebook plans to raise as much as $11.8 billion through the IPO, the biggest in history for an Internet company. Saverin’s stake is about 4 percent, according to the website Who Owns Facebook. At the high end of the IPO valuation, that would be worth about $3.84 billion. His holdings aren’t listed in Facebook’s regulatory filings.

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Eduardo Saverin, co-founder of Facebook, in New York City. Photographer: Jason Kempin/Getty Images for Common Sense Media

Saverin, 30, joins a growing number of people giving up U.S. citizenship, a move that can trim their tax liabilities in that country. The Brazilian-born resident of Singapore is one of several people who helped Mark Zuckerberg start Facebook in a Harvard University dorm and stand to reap billions of dollars after the world’s largest social network holds its IPO.

“Eduardo recently found it more practical to become a resident of Singapore since he plans to live there for an indefinite period of time,” said Tom Goodman, a spokesman for Saverin, in an e-mailed statement.

Saverin’s name is on a list of people who chose to renounce citizenship as of April 30, published by the Internal Revenue Service. Saverin renounced his U.S. citizenship “around September” of last year, according to his spokesman.

Singapore doesn’t have a capital gains tax. It does tax income earned in that nation, as well as “certain foreign- sourced income,” according to a government website on tax policies there.