Rob Green, who has been interim finance director of Manchester Building Society since 2015, stepped down from the role for personal reasons.
The company is searching for a replacement and expects to make an appointment in due course.
Manchester Building Society said in mid-March that it continues to evaluate the possibility of one or more transactions with "non-mutual organizations" as it seeks to resolve a shortfall of common equity Tier 1 capital against its regulatory combined buffer requirement. The lender booked a full-year 2016 loss of £3.4 million and said its accounts had for the second straight year set out a "material uncertainty" regarding its long-term future.
It also said it continues to believe that it is in the best interests of its members to pursue a claim against former external auditor Grant Thornton LLP, although any case would not come to trial before 2018.
Manchester Building Society withdrew from the residential lending market after it revised its accounting method for long-term mortgages and interest rate movements upon learning that its previous method failed to comply with international accounting standards. It is pursuing legal action against Grant Thornton over the audit services and advice provided by the firm from 2006 through 2013.