Tesco, the beleaguered British supermarket chain, has appointed BBH to handle its creative account without a pitch, as it looks to turn its business around.

Tesco, which spends around £120m ($180m) annually on advertising in the UK, has ended its two-year relationship with Wieden + Kennedy in the hope of recovering its tarnished reputation.

As a result, BBH has parted ways with upmarket grocery retailer Waitrose, due to conflict rules.

Neil Munn, chief executive of BBH Group, said: “A unique opportunity has presented itself with Tesco and we are looking forward to working with Dave Lewis and his team. This has meant that we have had to part company with Waitrose.”

BBH founder Sir Nigel Bogle added: “Waitrose is an extraordinary business and brand. Working with The Partnership has been a pleasure and a privilege. We are very proud of the work we have created together.”

The move follows a damaging 12 months for the supermarket, which is under investigation over accounting irregularities, and was forced to suspect eight executives, including UK managing director Chris Bush, pending the results of the probe.

The supermarket has come under pressure from German discount grocers such as Aldi and Lidl, with like-for-like Christmas sales down by 2.9%.

Unilever’s Dave Lewis joined as chief executive in September, while last month Tesco appointed Robin Terrell as its new top marketer, only six months after handling the role to Jill Easterbrook.

Last week, Tesco announced details of a plan to cut costs by £250m ($380m) a year, with measures including the closure of its current company headquarters and up to 100 stores.