Dublin - Shares in RSA Insurance dropped 13% to hit a 17 month low on Monday after it suspended three executives at its Irish business while it investigates issues in the unit's claims and finance functions.
RSA said it has suspended the Irish unit's chief executive Philip Smith, chief financial officer Rory O'Connor and claims director Peter Burke over "issues in the Irish claims and finance functions" identified in a routine internal audit.
Neither the company nor Ireland's central bank has given details of the problems.
In a statement on Sunday RSA said that while the problems were serious they would not have a material long-term impact on the company. It said it has a robust capital position and is committed to its dividend policy.
The insurer's shares plunged at the open on Monday to hit their lowest since June 2012 and were 13% lower at 105.1 pence by 08:20 GMT.
"The words 'reserving issues' and 'claims issues' strike fear into the hearts of management, investors and regulators of insurance companies - and not without good reason," said Eamonn Flanagan of Shore Capital Stockbrokers.
"Mercifully, although extremely damaging for the group's reputation and credibility in Ireland, these issues are unlikely to topple the group."