Wiring more businesses for high-speed data, Comcast Corp. has laid 50 miles of fiber-optic transmission lines throughout Center City and University City.

The $30 million project offers companies on commercial corridors such as Market Street superfast data speeds. It extends the Comcast backbone network to 3,000 Philadelphia businesses and big institutions, among them the University of Pennsylvania and the Thomas Jefferson University Hospitals complex.

"This was definitely one of the larger builds the company has undertaken," said David Dombroski, regional vice president for Comcast Business. "The goal was to put the best possible network in our hometown."

Verizon Communications Inc., a big competitor to Comcast in business and residential telecom services, is nearing the end of the build-out of its FiOS fiber lines in Philadelphia.

Comcast's fiber lines in Center City run between the Delaware River and the Schuylkill on the east-to-west axis, and between Spring Garden and South Streets north to south. The fiber lines go on to cross the Schuylkill and run throughout University City.

Typically, Comcast waits for a business to order the service to run the fiber to it. In this case, Comcast looked at potential demand and ran the fiber lines in front of those companies, anticipating that they would order it.

Comcast executives have said competing telecom companies have neglected to upgrade their business networks, opening the door for Comcast to expand into that segment.

Comcast's business services division is one of its fastest-growing units, with about $5 billion a year in revenue.

It launched its fiber-optic project in Philadelphia in June 2015, coordinating with the city for the permits.

Dombroski said the project would be completed by January.

"We didn't delay, and we didn't miss," he said of the fiber build-out.