Billionaire U.S. investor Warren Buffett will help raise money for President Barack Obama's re-election effort at a $35,800-a-ticket fundraiser next month in Chicago, an Obama campaign official said on Wednesday.

Buffett will attend the Oct. 27 event at a private home on Chicago's North Shore that is expected to include major donors to Obama's 2008 presidential run. The Democratic president, who is not expected to attend, is running for re-election in 2012.

Buffett, the legendary chairman of Berkshire Hathaway Inc., has landed in the center of a growing political battle over Obama's proposal to raise taxes on the wealthy by inspiring the so-called "Buffett Rule."

Buffett wrote a column last month saying rich people like him often pay less in taxes than those who work for them because of loopholes in the tax code, and can afford to pay more.

Obama cited Buffett on Monday in proposing a minimum tax rate for people earning more than $1 million a year. Republicans have condemned the plan as class warfare.