Glenborough Realty Trust has selected Richards Barry Joyce & Partners as the exclusive leasing agent for its downtown Boston office building at 99 Summer St.

The owners of 99 Summer St. have chosen Richards Barry Joyce & Partners of Boston as the exclusive leasing agent for the Class A office tower in the heart of Boston’s Financial District.

The announcement comes two months after Glenborough Realty Trust of San Mateo, Calif., bought the building for $68 million from Paradigm Properties and the Carlyle Group.

The office tower holds 271,980 square feet of rentable space and is only 3 percent vacant. Michael Joyce, a partner at Richards Barry Joyce, said that while some leases will expire in 2004, a majority of tenants have already renewed. However, he said that there is 30,000 square feet of space that may become vacant in the near term and that Richards Barry Joyce is actively showing the building to prospective tenants.

Rents will likely range in the $30s per square foot, according to Joyce.

Joyce, along with Richards Barry Joyce Associate Thomas Ashe, will lead the marketing efforts for 99 Summer St.

“It’s exciting,” Joyce said. “It’s good to see a new owner in Boston, because it’s [the commercial investment market] been dominated by other [real estate investment trusts].”

The building, with a granite facade and well-known red pyramidal roof, is the first downtown Boston property for Glenborough, which holds 1.2 million square feet of space in Canton, Lexington, Marlborough, Westborough, Westford and Weymouth.

John Conley, director of leasing for Glenborough, said that Richards Barry Joyce was chosen as the exclusive agent for its first Boston property from among a short list of competitors. Conley said the four commercial real estate firms that made the list all had called Glenborough with inquiries about becoming the building’s leasing agent. Glenborough didn’t solicit any other firms.

“If others weren’t interested enough to call then we figured that they weren’t interested enough to lease the space,” Conley said.

In the end, Richards Barry Joyce was chosen over Cushman & Wakefield, Lincoln Properties and Spaulding & Slye Colliers, which handled the leasing chores under the previous ownership group.

“We felt that whoever we hired would do a pretty good job but at the end of the day, it came down to the fact that we felt very strongly about Michael Joyce,” Conley said. “We’ve done a majority of our work outside Boston with Richards Barry Joyce.”

Richards Barry Joyce has leased at least 50 percent to 60 percent of Glenborough’s Massachusetts portfolio over the past five years. Out of its 1.2 million square feet of space outside Boston, Richards Barry Joyce leased 500,000 square feet.

While Joyce and Ashe will be faced with a slow commercial real estate market presently skewed in favor of tenants, Joyce said he’s optimistic that his team will be successful in filling any vacancies that may arise at 99 Summer St.

He said that he expects the building will attract financial, law and professional service firms, all of which are likely candidates to be seeking a Financial District address.

“With One Lincoln St. next door, that shifts a lot of people down into the area,” he said.

Joyce said that the building’s amenities will also help its popularity. Aesthetically, 99 Summer St. features all the aspects of Class A office space, including a five-story atrium lobby with marble finishes, cascading office levels, plantings and skylights, wood-framed doors, glass vs. sheetrock in some offices and nine-foot ceilings.

“All the little things were done well,” Joyce said. “That’s an asset to re-leasing space.”

The building also has parking, a salon, restaurants and a coffee shop. It’s also within walking distance to Downtown Crossing, Post Office Square, Boston Common and the Boston Waterfront.

To the Core

Glenborough purchased 99 Summer St. on July 22, using the 1031 Exchange tax program, which allows a company to sell one property and roll the tax-deferred profits into another purchase. The Summer Street building fit perfectly for Glenborough because it was selling a Denver property for about the same price, $68 million. Glenborough had also purchased another property from one of 99 Summer St.’s previous owners, the Carlyle Group.

Glenborough is looking to further expand its downtown Boston presence. Conley said that, over the next three to five years, the trust will be selling its properties in non-core markets and expanding holdings in seven of its premium markets, including Boston.

Glenborough is focusing on multi-tenant, Class A properties in the $25 million to $75 million range. Conley said that one of the attractive assets of 99 Summer St. was that it had 40 tenants, meaning that one vacancy wouldn’t put a damper on the entire building’s revenue.

“A lot of it will depend on our ability to find buyers for these other buildings,” Conley said of future investments in the Hub. “There’s no set timetable.”

But Conley said that Glenborough is definitely keeping its eyes open for opportunities.

Glenborough’s national portfolio features 67 properties with a total of 11 million square feet of space. The company’s core markets include Washington, D.C., Southern California, New Jersey, Boston, Northern California, Chicago and Denver.