KBS Realty Advisors of Newport Beach, Calif., has signed 23,116 s/f in lease renewals and expansions at its 625 Mount Auburn St., a three-story, class-A office structure located one mile west of Harvard Sq.. The 625 Mount Auburn St. leases consist of a 5,147 s/f expansion by Charles River Analytics; 13,478 s/f expansion and renewal by Mount Auburn Professional Services; and a 4,491 s/f renewal by Ophthalmic Consultants of Boston. Curtis Cole of CBRE represented Charles River Analytics in its lease, while Robert Fitzgerald and Adam Brinch of CBRE brokered the deal for KBS. Fitzgerald represented both KBS and the tenant in the Mount Auburn Professional Services transaction. Julie Gray of McCall & Almy represented Ophthalmic Consultants of Boston in its lease, while Fitzgerald and Brinch represented KBS. The 136,585 s/f 625 Mount Auburn St. is currently 99% occupied and features a three-story, 50,000 s/f wing and a two-story atrium lobby. Also included are new systems, modern exercise facilities and a shared conference room. "While East Cambridge is getting all the hype, the West Cambridge submarket has also recovered nicely since the trough of the market," said KBS senior VP/asset manager Shannon Hill. "High-quality assets like 625 Mount Auburn Street are seeing strong interest from tenants that require a Cambridge address." KBS-affiliated companies own three other properties in the Boston metropolis, including the Rivertech Buildings, a 285,772 s/f property in Billerica; 825 University Ave., a 166,574 s/f office building in Norwood; and the recently acquired 50 Congress St., a 179,872 s/f landmark office in Boston's Financial District. KBS Realty Advisors is a private equity real estate company and SEC-registered investment advisor founded in 1992. KBS Realty Advisors and its affiliated companies have completed transactional activity of approximately $30 billion via 14 separate accounts, six commingled funds, five sovereign wealth funds and five non-traded REITs.