Realogy's parent company is planning a $1 billion IPO, though some say the move is largely debt-driven.

The parent company of Realogy, which owns Century 21, Coldwell Banker, Better Homes and Sotheby’s International Realty, is hoping to raise $1 billion today in an initial public offering.

The IPO is a full circle for Domus Holdings, Realogy’s owner, which was bought out by Apollo Global Management in 2006 in the largest buyout ever in real estate. Here’s what we know about the upcoming IPO:

• Apollo Group took Realogy private for $6.65 billion in December 2006, and it owns 66 percent of Domus, while Paulson & Co. owns 21 percent, according to Reuters.
• Even after the IPO, Apollo will maintain a majority of voting power in the company.
• Many outlets are pegging debt relief as a big reason for the IPO; Domus has $7.23 billion of debt on its books, but after the IPO – during which Apollo and Paulson will convert $2 billion of convertible notes into shares – that load will decline to $4 billion.
• As HousingWire pointed out, Domus’ 2011 revenue was $4.09 billion, but it’s losses increased quite a bit from $99 million in 2010 to $441 million. Given the recent pick-ups in housing, though, the company says it’s optimistic about the future.