Comcast is already Philadelphia's largest office user ahead of the completion of its Comcast Technology Center, but its growth requires even more space.

The telecommunications giant has expanded and extended its lease at Three Logan Square, bringing its total footprint in the Brandywine Realty Trust-owned building from 230K to 300K SF, the Philadelphia Inquirer reports.

Comcast's lease at Three Logan Square, at 1717 Arch St. across from its Comcast Center headquarters, was set to expire in 2018. Its new lease, brokered by Binswanger CEO David Binswanger, will run until 2023. Comcast's total footprint in Downtown Philadelphia outside of the Comcast Center now totals 590K SF, with 200K SF at neighboring Two Logan Square and 90K SF in nearby Centre Square.

With the Comcast Technology Center almost topped off after a small hiccup, completion is expected in 2018. At that point, with its ownership and full occupancy of the two tallest buildings in Philadelphia — both developed by Liberty Property Trust — and the above leases, Comcast's total footprint in its home city would be 3.2M SF.

The leases remain necessary for Comcast's usual operations and growth because the CTC will house new operations for emerging technologies, as well as studios for its local NBC and Telemundo affiliates. Comcast's growth has been so strong that it is rumored to be planning a third skyscraper between Arch and Cherry streets and 19th and 20th streets due to a series of property buys made on the block by both the company and Liberty Property Trust, the Inquirer reports.