Silverman was previously global director of corporate media relations at aerospace firm Honeywell.
Before that he held positions at Merrill Lynch and was a Dow Jones journalist.
The agency has also expanded its Dubai office with the appointment of another partner, Alex Blake-Milton. He has been corporate comms chief at Commercial Bank of Qatar. Previously he worked for Standard Chartered as Middle-East and Asia corporate affairs chief.
Brunswick senior partner Susan Gilchrist said the agency was still expanding its Middle-East operations.