Burger King's parent company expects to raise up to $400 million in an initial public offering and said it will use the proceeds to pay down debt, according to regulatory documents filed Thursday.

Burger King Holdings Inc. didn't specify a per share price, what percent of the company's shares would be offered or set a date for the IPO, according to a copy of the registration statement to the Securities and Exchange Commission.

It has lost ground in fierce competition with rivals McDonald's and Wendy's. McDonald's Corp. is the leader in the fast food industry while Wendy's International Inc. has been battling with Burger King for second place among U.S. hamburger restaurants.

McDonald's had a 45 percent market share in 2004, while Burger King and Wendy's each had 14.2 percent, according to Technomic Inc.

Burger King Holdings said in the filing that it earned $47 million on revenues of $1.94 billion in the fiscal year that ended June 30, compared to $5 million on revenues of $1.75 billion the previous year.

Independent franchisees own about 90 percent of Burger King's more than 11,000 restaurants worldwide, while the rest are company-owned. Several large franchisees filed for bankruptcy over the past decade, and Burger King cut its ties in October with the National Franchisee Association.