Investment firm Legacy Partners Commercial Inc. of Foster City has purchased three Torrey Pines life sciences buildings for $51.25 million, according to CoStar Group. The seller was Pfizer Inc.

The buildings are in a complex known as Torrey Ridge Science Center, at 10578, 10614 and 10628 Science Center Drive. A statement from brokerage firm CBRE, which represented the seller, said the total 340,000 square feet of available space in the three buildings represents the largest block of vacant laboratory space in San Diego County.

The acquisition was a joint venture between Legacy and an affiliate of Chicago-based Walton Street Capital LLC. The venture has retained CBRE to provide leasing services.

The joint venture’s planned capital improvements include upgrading lobbies and landscaping, adding on-site amenities and providing prominent monument signage for new tenants, according to CBRE.

Ted Tapfer, Legacy’s managing director for San Diego and Orange County, said in the statement that the acquisition provides an opportunity “to reposition the three buildings as a cohesive, Class-A life science business center that will offer a multitude of space options to the biotech community.”

The three LEED-certified office and laboratory buildings were built in 2003 and 2004.