The Co-operative Bank lost around 25,000 current accounts and saw the withdrawal of £400m in savings cash during the first half of the year following uncertainty over its future.
However, in a statement of Thursday (10 August), the troubled bank said its losses narrowed over the said period to £135.2m from £177m last year.
The Co-operative Bank agreed a £700m rescue package in June and said that the deal was "on track" to be completed by September.
It was initially rescued from collapse by a group of hedge funds in 2013, after the bank's property loans portfolio contributed to a £1.5bn hole in its finances.
In February this year, having failed the Bank of England's capital adequacy requirements, the Co-op was put up for sale again.
However, the sale was subsequently dropped after existing investors agreed to a rescue deal, which will see them swap their debt for a stake in the bank. The Co-operative Group's stake in the bank will fall from 20% to about 1% as a result.
Chief executive Liam Coleman said the restructuring would "secure the future of the Co-operative Bank as a viable stand-alone entity."
Despite the loss of 25,000 customers, the bank still has 1.4 million current account holders.
"The vast majority of customers have remained very loyal as we have progressed the sale and capital raise process and I am extremely grateful for their ongoing support. Of course, there is more hard work ahead, and, like other banks, we recognise there are risks to the UK economy, but this is a great bank and we are positive about the future," Coleman concluded.