Athenahealth campus is for sale, but it aims to stay put in Watertown — as a tenant

Athenahealth has been regrouping after a tumultuous period that included its sale and cofounder Jonathan Bush’s resignation. Associated Press

There have been a lot of changes at athenahealth over the last few years. The latest one will change the formerly highflying heath data IT company from a landlord into a tenant.

In a deal that real estate experts say could fetch hundreds of millions of dollars for athenahealth’s new owners, the company is selling its 29-acre campus on Arsenal Street in Watertown.

But athenahealth is not moving. As part of the sale, the company says, it would sign a long-term lease with any new owner. Selling the Arsenal on the Charles campus is a way to capitalize on the market in what has become a hot corner for the region’s tech and life-science industries.

At the same time, it allows athenahealth — bought by a pair of private equity firms in February for $5.7 billion — to get out of the business of managing a huge office complex.

“Since the change in our company ownership earlier this year, we at athenahealth have been striving to create a thriving ecosystem that delivers accessible, high-quality and sustainable health care for all,” the company said in a statement. “Shifting from property ownership and management will bring us closer to realizing that vision, and we expect that transition will be seamless for our Watertown employees.”

Cofounder Jonathan Bush once envisioned athenahealth filling the entire 11-building, 830,000-square-foot Arsenal on the Charles, which is part of the old Watertown Arsenal campus. But the company’s growth slowed, and last year Bush resigned amid a hostile takeover bid that ended with athenahealth in the hands of Veritas Capital and activist investors Evergreen Coast Capital. They merged it with a former General Electric subsidiary, Virence Health, but pledged to keep the headquarters in Watertown, where athenahealth employed about 2,000 people before the takeover.

The company will sign a long-term lease for about the same amount of office space it currently occupies — roughly 350,000 square feet — said Dave Pergola, executive managing director at the real estate firm Cushman & Wakefield, which athenahealth hired to lead the sale. Much of the rest of the space is leased to other companies, but those leases will gradually turn over, and a master plan for the site allows at least 200,000 square feet of new development.

“There’s a foundation of a longterm lease with athenahealth and some other tenants,” Pergola said. “And then there’s a lot of upside.”

The campus sits in a stretch of eastern Watertown that is exploding with growth as companies spill out from neighboring Cambridge. Several new apartment and lab buildings have gone up in recent years, and construction is underway on a $400 million re-do of the old Arsenal Mall into a mixed-use project known as Arsenal Yards that would revamp its retail space and add housing and offices. For the office buildings, developers have been targeting life sciences companies. Last week, Kymera Therapeutics said it would move from Kendall Square to Arsenal Yards.

There are likely to be similar opportunities for the buyer of athenahealth’s campus, Pergola said. “This place is in the path of a lot of growth,” he said. “There’s a very large tech and biotech cluster happening in that area right now.”

Pergola said athenahealth hopes to have a buyer lined up by year’s end.