Archstone Inc., the U.S. apartment landlord that’s owned by the estate of Lehman Brothers Holdings Inc., is seeking as much as $3.45 billion in its initial public offering.

Archstone owns six apartment properties in Palm Beach and Broward counties.

The Englewood, Colorado-based company updated the amount sought in a regulatory filing Monday from a placeholder of $100 million. The company hasn’t yet specified the number of shares it will sell or the price range, and the amount sought is subject to change.

Lehman, which exited bankruptcy in March, took over all of Archstone in May. The defunct bank filed Aug. 10 to take Archstone public after battling billionaire Sam Zell to get full control of the company, setting the stage for a multibillion- dollar IPO later this year or early next.

Archstone, which plans to organize itself as a real estate investment trust, plans its IPO as shares of U.S. apartment REITs have gained 222 percent since dropping to a low in March 2009, outperforming the broader Bloomberg REIT index and the Standard & Poor’s 500 Index.

Rental revenue at Archstone in the three months through Sept. 30 increased 8.3 percent to $272.7 million from a year earlier, the filing showed. The company booked a net loss of $176.6 million compared with profit of $106.2 million a year earlier.