UK bank CYBG said it would take another £150m charge related to an industry-wide scandal over mis-sold insurance policies, sendings its shares down as much as 10% today.
The company became Britain's sixth largest bank following its purchase of rival Virgin Money.
It also said today that short-term prospects in its key lending markets - homeowners and small businesses - were subdued due to uncertainty over Brexit.
Shares in the owner of Clydsedale Bank and Yorkshire Bank fell to their lowest since June 2016, when Britain voted to leave the European Union.
The stock has lost well over a quarter of its value since the start of 2018.
The bank reported a statutory loss before tax of £164m for the year ended September 30, including a £352m charge related to the mis-selling of payment protection insurance (PPI).
UK banks have together had to pay out billions of pounds in compensation in the country's costliest-ever consumer scandal after regulators determined they had sold expensive PPI products to people who sometimes didn't need them.
Analysts said the extra £150m provision was larger than expected.
CYBG also said Brexit uncertainty had hit confidence among small and medium-sized enterprises.
"We took a position in 2016 that Brexit would lead to lower economic growth environment.
"I think you are seeing some of that. We are seeing inertia in SMEs and their investment profiles," the bank's chief executive David Duffy - a former AIB CEO - said.
CYBG forecast its net interest margin - the difference between what banks earn from loans and pay for deposits - would fall to 160-170 basis points (bps) in its new financial year from 178 bps in the one just ended.