MediaMath Inc. will be moving its headquarters downtown to 4 World Trade Center. The global technology firm has signed a 15-year lease with Silverstein Properties Inc. for 106,000 square feet.

Early next year, MediaMath will consolidate more than 300 employees at 4 WTC from three existing Midtown offices, totaling about 90,000 square feet, at 1440 Broadway, 1301 Avenue of the Americas and 535 Madison Ave. MediaMath will fill three floors, the 44th through 46th, at 4 WTC, a 72-story, high-tech, state-of-the art tower that opened in November 2013 at the 16-acre World Trade Center site.

John Seligman, a partner at Davis& Gilbert, represented MediaMath.

Skadden, Arps, Slate, Meagher & Flom counsel Russell Wohl represented Silverstein.

The 450-employee technology company has about 300 employees in Manhattan, and projects it will add 200 jobs this year and create some 1,000 new jobs in the city over the next five years.

CEO Joe Zawadzki said in a statement that MediaMath “has experienced staggering growth over the past few years and this move is both momentous and rewarding… We look forward to bringing our talent, energy, and culture to lower Manhattan and continuing to expand our business at 4 WTC among the growing downtown technology and media community.”

The overall asking rate in downtown Manhattan in proximity to 4 WTC is about $57 per square foot with a class-A rental rate of about $63 per square foot, according to Savills Studley’s July report.

“I am thrilled to welcome MediaMath, which represents the technology, advertising, media and information companies driving the city’s new economy and downtown’s future,” Silverstein Properties chairman, Larry Silverstein, said in a statement.

MediaMath considered other locations in New York and New Jersey, according to joint new release issued by Gov. Andrew Cuomo and Mayor Bill de Blasio. An incentive package, including a $5.8 million a federally funded Job Creation and Retention Program grant jointly offered by Empire State Development and New York City Economic Development, was a major factor in keeping the company in New York City as well as enabling the company’s move downtown.

“The state is proud to support the company’s major expansion in New York and we look forward to their continued growth,” Cuomo said in a statement.

“MediaMath’s move to 4 World Trade is yet another big step in the resurgence of lower Manhattan and the growth of New York City’s tech ecosystem,” de Blasio said in a statement. “This is a career sector we want to expand because it has so much economic mobility for its workforce.”

MediaMedia, which was founded in the city in 2007, was the first to introduce demand-side platform, a digital-advertising management system. It claims that its TerminalOne Marketing Operating System, “provides 4,000 advertisers a more efficient way to reach consumers.”

MediaMath’s growth is a “testament to the market’s need for a transformation in digital marketing through software,” Zawadzki said. The technology group has expanded its reach across five continents to 12 global locations, including Boston, Chicago, Miami, San Francisco, London, Paris, Singapore, Tokyo and Brazil.

The Port Authority of New York and New Jersey and the City of New York also have leased space at 4 WTC. According to Silverstein’s news release, with MediaMath’s new lease, 70 percent of the 7.4 million-square-foot 1, 4 and 7 World Trade Center has been leased. Silverstein also said that all of the retail space at the site, as well as the WTC transit hub involving PATH trains and 11 subway lines, will open in 2015.

A CBRE brokerage team led by Harly Stevens, senior vice president, and Michael Rizzo, vice president, handled the lease for of MediaMath.

Silverstein Properties’ Jeremy Moss, director of World Trade Center leasing, and CBRE’s CEO Mary Ann Tighe; Stephen Siegel, chairman, global brokerage; Ken Meyerson, vice chairman, consulting; and Evan Haskell, vice president, agency group, negotiated the lease on behalf of the landlord.