Elkus Manfredi Architects

One of the most sought-after new buildings in tech supercluster Kendall Square has landed a blue-chip tenant in Facebook to accommodate the social media giant’s Cambridge expansion strategy.

Facebook is leasing 129,636 square feet on three floors at 100 Binney St., part of the Alexandria Center at Kendall Square complex, a spokesman confirmed. The new facility will enable Facebook to expand its Cambridge workforce from 150 to 650, the Boston Globe reported. The offices will house machine learning divisions and a connectivity lab working on connecting the developing world to the Internet.

Facebook will join Bristol-Myers Squibb Co., which leased 400,000 square feet at 100 Binney St. in 2015 for a consolidation of research facilities in Waltham and Wallingford, Connecticut, with an occupancy date in early 2018.

Alexandria Real Estate Equities executives reviewed multiple proposals for the remaining space in the 10-story, 429,000-square-foot building over the past year. They were in talks with five tenant prospects this summer, executives said during a conference call with analysts in August.

Alexandria is poised to bring more office and lab space to the East Cambridge market in the wake of two recent acquisitions. It’s building a 172,500-square-foot speculative office and lab building at 399 Binney St. on a previously approved building site at the 644,000-square-foot One Kendall Square campus it bought last year for $725 million.

And in April the Pasadena, California-based REIT acquired a 3.6-acre property at 303 Binney St. for $80.25 million. The longtime owner and occupant, Metropolitan Pipe and Supply Co., has acquired 30 Innerbelt Road in Somerville for relocation.

Low vacancies and steady demand from industry-leading life science and tech tenants pushed East Cambridge asking lab rents to $75.48 per square foot in the second quarter, Transwestern Consulting Group said in its mid-year 2017 bioSTATus research report.