Jasinski will spend half her time working on marketing for Miles Calcraft Briginshaw Duffy and Elvis, with the rest spent co-ordinating marketing across the UK group, which also includes Dare, Band & Brown and Identica.
In her group role, Jasinski will attempt to improve the profile of the Cossette UK group and identify group-wide new-business opportunities. She will report jointly to Helen Calcraft, the chief executive of MCBD, and Gregor Angus, Cossette's executive vice-president.
Jasinski said she hopes to "harness the potential" that has not yet been tapped into across all of the businesses in the group. Calcraft added: "Increasingly, clients want to know a business' capabilities to work flexibly across a range of disciplines."
Jasinski joined Leo Burnett and Arc last year, and before that worked in similar roles at Partners Andrews Aldridge and Rainey Kelly Campbell Roalfe/Y&R.