FMC Corp. has been one of the region's quiet giants.

With $3.9 billion in sales in 2013, the specialty-chemical company is one of Philadelphia's most significant corporate residents. But in terms of household names, it's no Comcast.

That might change a bit now that FMC has decided to move to its own trophy tower at 30th and Walnut Streets. The edifice - to be topped with FMC's brand - will certainly make the firm more visible.

Groundbreaking for the 49-story, $385 million tower is set for Wednesday. Completion is expected by mid-2016. At that point, FMC will move 545 employees from 1745 Market St.

The project is being developed by Brandywine Realty Trust, another of the region's top 50 public companies, based on market capitalization.

FMC Tower will anchor Cira Centre South, Brandywine's ambitious attempt to further extend the Center City skyline to West Philadelphia.

Cira Centre South follows the Cira Centre, the 29-story office high-rise Brandywine completed in 2006 across the street from Amtrak's 30th Street Station.

FMC Tower is the largest element of the development package. Evo, a 33-story tower of student housing, is being erected at the north end of the block. It will have space for 850 residents when it opens in September.

Between the two buildings is a 1,600-car garage, which Brandywine is topping with a one-acre sward of green space accessible from both towers, as well as from street level.

Overlooking everything will be the FMC Tower, which Brandywine chief executive officer Jerry Sweeney called the city's "first vertical neighborhood."

By that, he meant its 861,000 square feet will have its own ecosystem of office, retail, and residential space.

There will be 622,000 square feet of office space, 61 percent of which is already leased to FMC.

The University of Pennsylvania has committed to an additional 100,000 square feet.

There will be 268 residential units, of which about 100 will be furnished and have full concierge service.

Also planned is about 10,000 square feet of retail, including a bar/restaurant, and a floor of amenities such as a state-of-the-art fitness center and swimming pool.

A reclusive FMC employee could theoretically never leave the building.

Brandywine, of course, is not looking for that to be the norm. Rather, it sees the FMC Tower, along with the rest of Cira Centre South, as creating a vibrant community where none now exists.

Counting employees at the FMC Tower and the redeveloped 30th Street post office and residents at the Evo and FMC towers, Sweeney said there would be 9,000 people living and working in what now is a bit of a dead zone between University City proper and the Schuylkill.

"This will have a wonderful ripple effect," Sweeney said. "It represents a very exciting step in the evolution of that part of the city."