Google is close to finalizing plans to expand its already sizable footprint in Kendall Square in Cambridge.

The Internet giant is currently in negotiations with Boston Properties to add upwards of 70,000 square feet to its Cambridge portfolio, according to multiple commercial real estate insiders.

The expansion will add 4 Cambridge Center to the roster of properties Google now inhabits. The company currently occupies approximately 250,000 square feet at 3 and 5 Cambridge Center, as well as 141 Portland St.

Sources tell Banker & Tradesman that Boston Properties is currently shuffling tenants around those three Cambridge Center properties to accommodate Google’s hopes for a bigger home at 4 Cambridge Center.

The landlord is also considering a connector, like a pedestrian bridge or other similar structure, to connect the three properties. Google pushes for connectivity among its workers and proximity to public transportation, and 4 Cambridge Center is farthest away from the Kendall Square T station.