Owner Ed Gardner is selling the 511 Congress St. building through a sealed bid system. The property includes a 130,000-square-foot office/retail building as well as a 265-space parking garage. Michael Kelley / The Forecaster

PORTLAND — After five years of rehabilitating 511 Congress St. into a modern,  attractive and landmark office building, local real estate broker Ed Gardner is ready to sell the property.

“He’s done all the stuff he has envisioned for the property. He loves this building. From what I have heard, he is not looking to buy something else. This is just a good time to sell this property,” said broker Matthew Cardente, owner of Cardente Real Estate.

The property, dubbed Ocean Gateway Plaza, is being sold via a sealed bid offering. Bids are due by Friday, Nov. 22. Selling a building via a sealed bid, Cardente said, allows for  “the market to dictate pricing.” The sealed bid approach will allow Gardner to compare the bids that come in as well as the terms of sale, something that is not possible through a traditional building sale.

Gardner purchased the building via sealed bid in 2014 for close to $12.4 million, more than $2.5 million more than it sold for in 2005. The building, built in 1973, sold for $3 million in 1995 and $8 million in 2002, according to city property records.

Shortly after purchasing the building, Gardner renovated the interior, exterior and lobby. In August, he opened the new 265-space Arts District parking garage behind the building, which is part of the building sale package.

Gardner referred all questions about the building and the sale to Cardente.

“Rebranding this property … along with planned renovations, will surely breathe new life into this pinnacle of Portland’s skyline,” Gardner said in 2014.

As part of the building improvements, art has been added to the main lobby and central courtyard along Congress Street. Michael Kelley / The Forecaster

Major tenants in the nine-floor building include radio ad agency Strategicmedia and accounting firm Honeck and O’Toole, which share the top floor; software company Model N and financial services company Northwestern Mutual on the sixth floor; law firm  Troubh Heisler, which occupies the sixth floor; and wood., an engineering and consulting firm with more than 34,500 square feet of space on the second, third and fourth floors. A collection of businesses, offices and services are housed on the first, fifth and eighth floors.

There is no firm date in terms of accepting an offer on the property, Cardente said.

It is the third large commercial building in a one-block stretch of Congress Street to be placed on the market in a little over a year.

The Time and Temperature building, a 12-story office building at 477 Congress St., was purchased at auction in October 2018 by TT Maine Venture, of Dallas, Texas,  for $9.3 million. In June, Alta Properties LLC in Newton, Massachusetts, and Connecticut River Capital, of Lebanon, New Hampshire, purchased 465 Congress St., a 10-story, 77,093-square-foot office building next to the Portland Public Library in Monument Square for $8.2 million.