NAI Hunneman has brokered multiple leases totaling 12,275 square feet of office space in Boston’s Financial District.

Bonny Doorakian and David Cooney, senior associates at NAI Hunneman, represented the landlord, Centurion Realty, in all five transactions at 77 Summer St. and 184 High St., according to a statement.

Career Collaborative, a nonprofit organization helping adults get and succeed at life-changing jobs, leased 3,911 square feet on the 11th floor of 77 Summer St. Kristin Blunt and Mike McElaney of Colliers Meredith & Grew represented the tenant.

RE/Max Office, a residential brokerage firm, leased 2,700 square feet on the second floor of 77 Summer St. Bonny Doorakian and Dave Cooney of NAI Hunneman represented the tenant.

TCognition Inc., an IT/software staffing, consulting and outsourcing services firm, leased 1,000 square feet. Doorakian and Cooney also represented the tenant in the transaction.

Apex Environmental, an environmental, health, safety and engineering firm, leased 2,332 square feet of space at 184 High St. Jim Griffin of GVA Thompson Hennessey & Partners represented the tenant.

Green Insurance, an insurance brokerage firm, leased 2,332 square feet of office space. Kevin Brown of Brown & Wagner represented the tenant.