The account was won after a review that included seeing credentials of 25 PR agencies, followed by a four-way pitch.
The contract comes after seven-year incumbent The Communications Business resigned the account earlier this year.
The agency will begin a wide-ranging external comms campaign later this month. The account will be led by associate director David Southern who will report to Shepherd and Wedderburn marketing director David Wallace.
Shepherd and Wedderburn has doubled its turnover in the last five years.