Tech firm Localytics will triple its office space as it relocates next March from 101 Arch St. in Boston’s Financial District to Center Plaza, the 717,128-square-foot office complex overlooking Boston City Hall Plaza.

Center Plaza is being repositioned by Shorenstein Properties, which acquired it in early 2014 for $307 million. One major tenant, the Federal Bureau of Investigation, will vacate 160,000 square feet at Center Plaza in 2017 when it moves to a new regional headquarters in Chelsea.

Shorenstein plans a $25-million redesign of the 900-foot-long ground-floor retail arcade. The project will also include a new conference center, bike room and rooftop renovations.

Localytics leased 55,000 square feet, up from its current 18,000 square feet at 101 Arch St. The company, which provides mobile app marketing and analytics services, was recently ranked 274th on Inc. magazine’s list of the nation’s fastest-growing private companies, and raised $35 million in funding during the first half of 2015.

CBRE’s Andy Hoar, John Butterworth, Kevin Kennedy and Suzanne Brown represented Shorenstein in the lease transaction. Localytics was represented by T3 Advisors’ team led by Greg Hoffmeister and Jon Frisch.