Reebok’s 65-acre former Canton headquarters is under agreement to a San Francisco investor with a portfolio of suburban office campuses in Greater Boston.

Spear Street Capital is expected to acquire the 65-acre property for approximately $80 million, according to The Real Reporter publication. Reebok vacated the sprawling complex on Royall Street in December after it opened its new headquarters in Boston’s Innovation and Design Building.

The Canton complex overlooking Route 128 was custom-designed for Reebok in the late 1990s with a focus on fitness amenities. The 518,000-square-foot office building includes a regulation basketball court and overlooks seven playing fields and a 400-meter track. The property also includes a 138,000-square-foot office and R&D building, a 14,000-square-foot manor house, a 10,000-square foot child-care center and two parking garages containing 1,200 spaces.

While the property was marketed as a potential corporate headquarters, there’s been speculation that the new owners will pursue a multitenant strategy. Spear Street was not immediately available for comment.

The San Francisco-based investor has targeted large office properties in Boston suburbs, most recently acquiring four buildings totaling nearly 500,000-square-foot at the Center at Corporate Drive in Burlington from The Davis Cos. for $133.5 million. In 2014, Spear Street paid $43 million to buy the 200,000-square-foot Riverworks converted mill complex in Watertown, a former Boston Scientific headquarters that has been broken up into multitenant space. It also owns the 1-million-square-foot Minuteman Park in Andover through a joint venture.

At the same time, Spear Street has disposed of urban properties including a pair of office buildings in Boston’s Fort Point and 226 Causeway St. for a combined $187 million in 2014 and 2015 respectively.

CBRE/New England marketed the Reebok property on behalf of Reebok’s German parent, Adidas Group. CBRE said it conducted more than 60 tours of the property last year.