SAN FRANCISCO (AFX) -- Burger King Holdings Inc. boosted the size of its planned initial public offering and now aims to raise almost half a billion dollars from the sale, according to a Securities and Exchange Commission filing on Tuesday. The fast-food chain said in the filing that it now plans to sell as many as 28.75 million shares for as much as $17 each, raising a maximum of $488.75 million. In a previous filing on April 24, Burger King had estimated its IPO would raise as much as $400 million. This story was supplied by MarketWatch. For further information see www.marketwatch.com.