The largest office building in downtown Westbrook is for sale.

One Riverfront Plaza has been vacant for more than a year. Disability RMS, a disability insurance provider and one of Westbrook’s largest employers, left for South Portland in January 2016.

The property owner was already struggling to keep up with the $20 million mortgage, and the loss of its core tenant was a death blow. Court documents show the U.S. National Bank Association filed a lawsuit against the property owner and eventually bought the building back at a foreclosure auction in February.

Now the bank is advertising the building to prospective buyers and tenants. Located on the bank of the Presumpscot River, One Riverfront Plaza has 134,000 square feet of high-end office space. A newly opened pedestrian bridge connects the office directly with restaurants and shops on Main Street.

City Administrator Jerre Bryant said a continued vacancy could hurt Westbrook’s downtown.

“If you bring in between 300 and 500 employees to the downtown on a daily basis, you’re going to bring business to the downtown,” Bryant said. “When it’s vacant, that’s not happening.”

One Riverfront Plaza is listed for sale through NAI The Dunham Group in Portland, and offers were due April 28. The listing does not include an asking price. The advertising materials tout the six-story building’s “excellent highway access,” “newer construction” and “absence of large block competition.” A request for comment from the real estate firm Friday afternoon was not returned.

Portland-based Boulos Property Management is also listing the building for lease at $16.50 per square foot per year.

“We have had some interest from prospective office users,” Drew Sigfridson, managing director and partner at Boulos Property Management, wrote in an email. “Most have had an interest in a portion of the building, not the entire building. We do not have any new signed leases for space at this point. It is a very attractive Class A office building and a great option for large office users in the marketplace.”

Sigfridson did not respond to a request for further comment.

When One Riverfront Plaza was built in 2004, the going lease rate was $19 per square foot per year. Starting in 2006, Disability RMS occupied most of the building. In 2014, the company announced its plans to move its 350 employees to South Portland when its lease in Westbrook expired in 2016. City officials told the Portland Press Herald they had done everything possible to prevent the move.

The building’s owner, a New Jersey investment firm called Pendleton Westbrook SPE LLC, was in financial trouble even before Disability RMS left at the end of January 2016. At the time, a report from a New York-based commercial real estate analysis firm showed that Pendleton had failed to make a balloon mortgage payment two months earlier and was asking for an extension. By August 2016, U.S. Bank filed a lawsuit against Pendleton over nonpayment of the $20 million mortgage. The banking group asked the court to approve a foreclosure sale and appoint Boulos Property Management to take over management of the empty building.

That sale took place Feb. 17. The price was $9.2 million, less than half of the building’s assessed value.

Bryant couldn’t say who has expressed interest in buying or leasing the property. He hoped for a locally based company to take over the entire building.

“They’ve received proposals,” he said. “I’ve heard nothing back from the bank or anybody else about what they received.”

When developer Tim Flannery built One Riverfront Plaza in 2004, the city constructed an adjacent parking garage with 540 spaces. Bryant said he expects the building’s next owner to take over that lease and cover the revenue lost when Pendleton stopped paying. The lease costs $13,770 a month, or $165,240 per year.

“It would be nice to get a real strong number of people coming into the downtown,” Bryant said.

Megan Doyle can be contacted at 791-6327 or at:

mdoyle@pressherald.com

Twitter: megan_e_doyle