Supermarket chain Woolworths will change an advertising campaign for car insurance after the Australian Securities and Investments Commission (ASIC) labelled it potentially misleading.

The ads, which appeared online and on buses, claimed “on average, our customers saved $240”.

This was based on a sample of 109 people who bought comprehensive car cover, comparing their new premium with their previous policy.

But the regulator is concerned about possible differences between the products.

Under Woolworths’ policies customers might have been insured for a lower sum, ASIC says.

The ads featured a disclaimer noting possible variations in cover, but the regulator says it was not prominent enough – especially on bus ads, which people have little time to read.

“When comparing products in an ad, the products should have sufficiently similar features to make the comparison relevant and not misleading,” ASIC Deputy Chairman Peter Kell said.

“The more a qualification is required to balance the information contained in the headline claim, the clearer and more prominently placed the qualification should be.”

Hollard Insurance issues Woolworths’ cover.

Last month ASIC raised concerns with Hollard subsidiary Real Insurance about funeral cover ads that had insufficient information on premium increases and inadequate price qualifications.