Image courtesy of Newmark

Lab developer Alexandria Real Estate Equities continues to unload portions of its Greater Boston portfolio, selling Cambridgeport and Waltham properties for a combined $306 million to a San Diego-based rival.

The latest transaction includes 640 Memorial Drive in Cambridge, which is leased to Sanofi, and 100 Beaver St. in Waltham. The buyer is Phase 3 Real Estate Partners, which has been developing lab space in Greater Boston in recent years.

Alexandria acquired the 225,504-square-foot Cambridgeport property in 2015 through a ground lease for $176.5 million and the assumption of $82 million in debt, according to an SEC filing.

The 3-story building is a former Ford Motor Co. factory repositioned by MIT Investment Management Co. as a biotech center. 

Alexandria had owned 100 Beaver St. in Waltham since 2005, paying $10.8 million for the 82,662-square-foot multitenant building.

As of the end of the third quarter, Alexandria owned 75 properties and development sites in Greater Boston totaling nearly 13.2 million square feet.

But the Pasadena, California-based REIT has been divesting non-core assets since early 2023 and recently dropped a large development planned in South Boston amid the local gut of lab space.

In December, Alexandria sold two industrial properties at 380 and 420 E St. where it had planned a new life science campus to industrial investors for a combined $87 million.

In June, the firm sold a five-building portfolio in Cambridge and Waltham for a combined $365 million, and the Riverside office park in Newton for $117.5 million after dropping plans for a lab conversion.

Phase 3 Partners has acquired properties in the suburbs and Boston’s Fort Point in recent years for lab conversions. In June, the company received approval for an office-to-lab conversion at 55 Summer St. in Downtown Crossing.