Athenahealth Inc., which provides electronic record and billing systems to hospitals and other medical industry clients, has agreed to buy the Arsenal on the Charles office campus in Watertown, the company said Wednesday.

Athenahealth will pay $168.5 million to acquire the 29-acre parcel from Harvard University, which is expanding in nearby Allston. The campus already serves as Athenahealth's headquarters, but executives said buying the property will allow them to expand the business in coming years.

Arsenal on the Charles includes 11 buildings totaling about 760,000 square feet. The complex, whose historic buildings date back 200 years, is located near the Charles River about 10 miles from downtown Boston.


"The Arsenal on the Charles' open and expansive architecture, outdoor campus feel, and proximity to Boston really fit with our culture and made it the logical place for us to expand," said Jonathan Bush, the company's chief executive.

The deal is expected to close next spring.

Casey Ross

Casey Ross can be reached at cross@globe.com.