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, Bloomberg reports.

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 whoownsfacebook.com. At the high end of the proposed IPO market capitalization, that would be worth about $3.84 billion. His holdings aren’t listed in Facebook’s regulatory filings.

Saverin, 30, joins a growing number of people giving up U.S. citizenship ahead of a possible increase in tax rates for top earners. The Brazilian-born resident of Singapore is one of several people who helped Mark Zuckerberg start Facebook in a Harvard University dormitory 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 made that move “around September” of last year, according to his spokesman.

Besides helping cut tax bills stemming from the Facebook, the move may also help him avoid capital gains taxes on future investments since Singapore doesn’t have a capital gains tax.