The largest owner of office buildings in Honolulu is considering selling its portfolio of six properties, a move that could result in a new dominant landlord controlling nearly 10 percent of the market.

Properties from downtown to Waikiki — Waterfront Plaza, Davies Pacific Center, Pan Am Building, First Insurance Center, Pacific Business News Building and Clifford Center — have been put on the market by Pacific Office Properties Trust Inc.

The San Diego-based company founded by local commercial real estate investor and University of Hawaii graduate Jay Shidler announced yesterday that it had retained a broker to explore selling the six buildings or finding a partner to invest in the portfolio.

The move follows unsuccessful attempts by Pacific Office to raise capital to reduce its debt and grow its collection of property. Pacific Office retained Wells Fargo & Co. subsidiary Eastdil Secured LLC to interest buyers or investors in the Honolulu office buildings.

The effort might not result in a transaction, but if successful it could dramatically reshape the geography of Pacific Office’s holdings and make someone else the largest office-building owner in Honolulu.

“We’re going to see what the market offers us,” said Larry Taff, executive vice president of Hawaii operations for Pacific Office.

Commercial real estate brokers said such an opportunity is rare in the local marketplace. “It’s going to be an opportunity for somebody to get a stranglehold on the market,” said Kalani Schrader, executive vice president in the office division at CBRichard Ellis. “It’s a big-ticket portfolio.”

Collectively, the six properties comprise almost 1.5 million square feet of leasable space, or almost 10 percent of Honolulu’s office market. The biggest property in the group is Waterfront Plaza, which includes Restaurant Row and contains 534,475 square feet of leasable space.

The Honolulu properties also represent the bulk of Pacific Office’s assets, and were the core pieces of real estate Shidler used to establish the company in 2008.

Besides the six Honolulu buildings, Pacific Office wholly owns one building in San Diego and one in Phoenix.

Shidler initially used nine office buildings — six in Honolulu and three on the mainland — that he owned through The Shidler Group to establish Pacific Office as a publicly traded real estate investment trust with stock traded on the American Stock Exchange.

Since then Pacific Office, with Shidler as chairman of the board, has grown its portfolio primarily through joint ventures, acquiring partial ownership between 5 percent and 32 percent in 16 office properties, including one in Honolulu, Bank of Hawaii Waikiki Center.

But the company also has struggled financially.

Pacific Office reported a net loss of $17.5 million for the nine months ended Sept. 30. The company has yet to report full-year results for 2010.

Among financial drags are two mortgage defaults, including a loan on the Pacific Business News Building that matured in April 2010 and has cost Pacific Office $800,000 in default interest and penalties through September. Negotiations to extend the loan are continuing.

Previously, Pacific Office attempted to sell stock to generate cash to reduce debt and expand its holdings, but those efforts didn’t produced desired results and were canceled.

For instance, Pacific Office announced plans in 2009 to sell about $350 million in stock in part to acquire distressed property.

The company arranged later to buy 12 office properties in California for about $306 million subject to completion of the stock sale, but the acquisition was called off and the stock sale was canceled after $25 million had been raised.

In January, Pacific Office announced new plans to sell about $350 million in stock in another effort to recapitalize the company and list shares on the New York Stock Exchange. But that offer was withdrawn after unfavorable response.

The most recent stock sale contemplated selling shares for between $7.50 and $8.50 each, and would have diversified ownership of Pacific Office, which is roughly 92 percent owned by its founders. Shares closed yesterday at $2.20.

Last month following the second aborted stock sale, the chief financial officer of Pacific Office, James Wolford, resigned and was replaced by Michael Burer, who was executive vice

president of operations for Pacific Office and a former senior vice president of finance for The Shidler Group.

The new plan to raise capital touts the value in the company’s Honolulu office buildings.

“Honolulu has always been seen as a high barrier-to-entry market in which achieving critical ownership mass is difficult and time-consuming,” James Ingebritsen, Pacific Office’s chief executive officer, said in a written statement. “We have a long and successful history of co-investing with institutions and believe this six-property portfolio is ideal for a new buyer to obtain a dominant position in the Honolulu office market or to seed a major joint venture that will acquire additional investments in the Honolulu market.”

Post-statehood boom galvanized Shidler Jay Shidler, a 1968 graduate of the University of Hawaii business school, did his first commercial real estate deal while a student at UH. He went on to start more than 30 companies across the U.S. worth billions of dollars, including The Shidler Group. In 2006 he donated $25 million to the UH business school with the goal of transforming it into one of the top 25 business programs at public universities nationally. The school was renamed the Shidler College of Business. Shidler, the son of an Army officer, lived here in 1949 and came back to attend UH after graduating from high school in Maryland. He said the experience of going to school in the post-statehood years when Hawaii’s economy was taking off presented a seemingly endless spectrum of possibilities, something that shaped his outlook in business. While at UH, he worked afternoons for real estate appraiser Philip Won and came across a Makiki property he believed could be developed. He helped in the development and received a cut of the property when it was built as the 1111 Wilder condominium on the slope of Punchbowl. Shidler and his wife, Wallette, a Kamehameha Schools graduate, live in Honolulu.