Platt joins the eight-strong team at BBS initially on a consultancy basis as part of ambitious growth plans to increase turnover 30% year-on-year.
Platt was previously UK managing director for Allied PRA, where he was responsible for establishing a new operations team and securing new business from international corporates.
Prior to his role at Allied PRA, Platt held the position of business tourism marketing manager at Marketing Manchester.
To achieve growth targets, BBS is now planning to roll out new strategic marketing services as well as expanding in existing markets.
BBS also plans to further spread its reach into the London, midlands and south east markets.
Ruth Robinson, managing director, said: "2013 is set to continue as a pivotal year for BBS. The appointment of Leo as business development director, which is a first for BBS, will contribute to the onward development of the business. Our ambitious growth plans will enable us to provide a broader range of services to a wider client base while maintaining our renowned friendly and client-focused approach."
Platt added: "It is with great pleasure I join the team at BBS. This is a hugely exciting time for the business. I look forward to playing part in developing BBS and contributing to its onward success."