Paramount Group Inc., a U.S. office landlord, is seeking as much as $2.5 billion in an initial public offering that would be the largest by a real estate investment trust in the U.S.

Paramount is offering 131 million shares for $16 to $19 apiece, according to a regulatory filing Thursday. Even at the low end of that range, the IPO would top a 2006 sale by Douglas Emmett Inc. that raised almost $1.6 billion, data compiled by Bloomberg show.

The company, which plans to qualify as a REIT, owns or has stakes in 12 office buildings in New York, Washington and San Francisco. The Bloomberg REIT Index has gained 21 percent this year, and is near its highest level since June 2007.

Paramount’s properties, which include San Francisco’s One Market Plaza and New York’s 712 Fifth Ave., were 92.1 percent leased to 260 tenants as of Sept. 30, the filing shows. Its New York buildings accounted for 76 percent of annualized rent.

Bank of America Corp., Morgan Stanley and Wells Fargo & Co. are managing the sale. Paramount plans to list its shares on the New York Stock Exchange under the symbol PGRE.