Britain's Co-operative Group, the mutually-owned supermarkets to funeral services group, said today it had written off the value of its stake in the struggling Co-operative Bank. 

Reporting its financial results for 2016, Co-operative Group said uncertainty about the value of the bank during its sale process made it prudent to value the group's stake in the lender at nil. 

It is the third consecutive reporting period in which the group has written down the value of its 20% stake, which it last valued at £140m in September. 

The write-off meant the group recorded a pretax statutory loss for 2016. 

The group said its operating profit rose by 32%, on growth in its core businesses of supermarkets, funeralcare, and insurance. 

The Co-op Bank's current sales process has drawn interest from multiple bidders after the ailing British lender put itself up for sale in February. 

Sources close to the process told Reuters that most bidders were interested in specific assets only as they saw little value in buying the whole group. 

Co-op Bank nearly collapsed in 2013 with a £1.5 billion hole in its capital after losses from problem real estate loans.

Bondholders ultimately took control of the bank.