Eduardo Saverin, the billionaire co- founder of Facebook Inc. From his facebook.

Eduardo Saverin, the billionaire co- founder of Facebook Inc.

EDUARDO SAVERIN, the billionaire co-founder of Facebook, renounced his US citizenship before a sharemarket float that values the social network at as much as $US96 billion.

Facebook plans to raise as much as $11.8 billion through the float, the biggest in history for an internet company.

Mr Saverin's relinquishing of US citizenship could reduce his tax bill. His stake in Facebook is about 4 per cent, according to the website whoownsfacebook.com. After the float, that would be worth about $US3.8 billion.

Mr Saverin joins a growing number of people giving up US citizenship before a possible increase in tax rates for top earners. The Brazilian-born resident of Singapore helped Mark Zuckerberg start Facebook in a Harvard dormitory.

''Eduardo recently found it more practical to become a resident of Singapore since he plans to live there for an indefinite period of time,'' his spokesman, Tom Goodman, said.

The 2010 movie The Social Network portrayed him as a scorned friend who provided the company's early financing and then was squeezed out. He sued Mr Zuckerberg and settled for an undisclosed amount.

Bloomberg