LONDON (Bloomberg) - Websites that compare insurance policies may not give consumers the full picture of where to find the best deal, the UK financial markets regulator said.

Few comparison websites give full details on coverage or deductibles, according to a review of 17 comparison websites by the Financial Services Authority (FSA) published today in London.

"We recognise that many consumers use these websites to search for insurance products," said Ed Harley, the FSA's head of financial promotions. "Consumers should shop around for the best deal, but it is important that they compare what's covered by a policy and not just focus on the price."

The number of websites that compare insurance policies in the UK. has jumped in the last three years, with the regulator estimating that comparison sites generated about 25 percent of car insurance policy sales in 2007. The FSA started its own website earlier this year for consumers to compare policies.

"This is a great start, but the FSA must go further," said Steve White, head of compliance at the British Insurance Brokers' Association in a statement. The association commissioned research that found that 84 percent of consumers find comparison websites confusing.

"Like brokers, comparison sites should guarantee their quotes," he said.

"We think we do provide clear information on policies, but it's an evolving market," said Jennifer Rose, a spokeswoman for Confused.com, a website started in 2003 that provides one million quotes a month. "We would welcome regulation of comparison sites as long as it doesn't stifle the positive steps websites have made."

The comparison site run by Tesco plc., the UK largest supermarket chain, said websites should do more to highlight their affiliations with insurance companies. Confused.com is owned by insurance company Admiral Group plc.

The FSA found no evidence that companies paid to have particular placement on the comparison sites, said FSA spokesman Adam Richards-Gray.