Co-operative Group Ltd. wrote down the value of its 20%stake in Co-operative BankPlc to £185 million as of the end of 2015, a year-over-yearreduction of 17%, The (U.K.) Guardian reported April 11, citing thegroup's annual report.

The drop in the stake's value indicates that the bank maynow be worth less than £1 billion, the paper noted, adding that it also meansthat the group's stake is worth less than the £333 million it injected in 2013to keep the lender afloat, the paper noted.

The bank, which recorded a full-year 2015 loss attributable to equityholders of £623.3 million, is expecting to post a loss for 2016 as well.