Some of the biggest names on the high street, including Arcadia, Debenhams and House of Fraser, have been caught up in an investigation into mis-selling of payment protection insurance (PPI).

GE Capital Bank was fined £610,000 yesterday for failing to train and supervise an army of 300,000 shop workers who try to persuade shoppers to take storecards and accompanying PPI.

The Financial Services Authority uncovered a string of failings by GE, the biggest operator of storecards. Other GE client retailers include Harrods, Toys ‘R’ Us, Halfords and Laura Ashley.

In a single year GE’s agents sold 850,000 PPI policies, which promise to pay off some of a storecard-holder’s debts if they lose their jobs or fall seriously ill. Some customers were not told that PPI was optional, the FSA found. Others were not told they were buying insurance. Others were not alerted to a fact box spelling out the exclusions.

Shop assistants receive incentives for selling storecards and the accompanying insurance, which was known as Account Cover and included other types of insurance.

Although a useful product for some people, PPI is regarded by some consumer groups as poor value with egregiously high premiums and low pay-out rates. It is sometimes sold to people never able to claim because they are self-employed or have a preexisting medical complaint.

The FSA said it was the responsibility of GE, not the retailers, to ensure customers were properly informed. The fine, the biggest so far for PPI failings, would have been £870,000 but GE earned a 30 per cent discount for agreeing to settle early. GE said it fully accepted the FSA’s findings and was honouring claims that would otherwise be rejected because of an exclusion.

One senior retail executive said, “It’s GE that’s been fined, not my shopworkers. We don’t do anything to mislead anybody.”