Home repairs group Homeserve said it had halted telephone sales and will retrain nearly 500 call centre staff after discovering possible mis-selling of its household emergency policies.
The FTSE 250-listed company, which insures against and repairs burst pipes, broken down boilers and electrical problems, suspended telephone sales last night after a review by accountant Deloitte.
Sales will not resume again until a staff retraining programme for employees had been completed, it added.
The problems were reported to centre on the scripts used by its sales team to explain pricing and policy details.
In a statement, the company said the review highlighted cases where the sales processes did not meet required standards.
Chief executive Richard Harpin said: "We have commenced a programme to retrain staff."
He added that it will resume marketing once it is confident "the sales processes meet the standards that we and our customers expect".
Shares in the group are expected to be hit hard by the news when the company resumes trading on Monday, even though it said it remains on track to hit market forecasts for the year to next March.
The company is valued at £1.6 billion and had seen its share price more than double over the past three years.
It has more than five million customers and 11.7 million policies across its businesses, which also include divisions in the US, France and Spain as well as the UK.