The consultancy will set the global comms strategy for Grundig and help promote the brand's sustainability agenda, as well as lead on comms creative.
Blurred, which was set up by chief executive Nik Govier with founding partners Katy Stolliday and Stuart Lambert in 2018, has a strong focus on working with clients that have sustainability at the heart of their operation.
Last year, the consultancy pledged to work with clients that meet a new framework based on the United Nations' 17 Sustainable Development Goals.
Grundig offers a range of home appliances with a "strong focus on sustainability, design and quality".
The brand is owned by Turkish consumer electronics and home appliances group Arçelik, which was named an industry leader in the Dow Jones Sustainability Index last year.
Govier said: "Grundig is a brand with a clear purpose and a vision to create a more sustainable future, which informs everything it does as a business.
"The depth of this commitment makes Grundig a dream client for Blurred, and we're looking forward to working with the Arçelik team to realise this ambition."