The agency was appointed following a pitch with several undisclosed agencies. It is not known if there was an incumbent.
A national campaign is expected to launch in mid-July and will include television, print, online and PR activity.
Bray Leino has been charged with ensuring that OMSCo capitalises on its existing position in the market and to expand consumer awareness of the positive benefits of organic milk.
The agency says it will tackle consumer misconceptions about the cost and benefits of organic milk and “encourage people to think about making organic milk a part of their daily routine”.
The OMCo is a 400-strong co-operative of organic dairy farmers and the UK’s leading suppliers of organic milk.
Richard Hampton, OMSCo sales and marketing director, says: “OMSCo has always appreciated the need for investment in consumer-focused communications. That’s why, despite the current climate, the most important thing for us to do is to build the organic dairy sector.”