The account was previously held by MediaVest Leeds, part of Publicis Groupe. It will switch with immediate effect. Robert Dyas has 95 stores in the south of England, selling DIY, kitchen, home and garden products. The 130-year-old chain plans 30 new openings by 2007.
It currently focuses its media spend on press and inserts, but MPG is understood to be looking at building up its television presence.
Dean Morris, marketing controller at Robert Dyas, said: "We were very impressed with the team at MPG. With their retail understanding and expertise, we believe they are the right media partner to help us grow our brand and expand our business operation across the UK."
The win brings MPG's new business billings for the year to date to £33m. Other accounts it has picked up include the £2m New Covent Garden Food Company brief and the Danepak relaunch, worth £4m.
Mark Craze, managing partner at MPG, said: "Robert Dyas is a dynamic retailer with aggressive growth plans and we are delighted to be working with them. This is a great win for us, vindicating our strategy of providing clients with the most senior talented teams."