The cost of motor insurance for young women drivers has increased by 32% over the past six months due to the impact of a ban on gender-based pricing, according to figures published by Towers Watson.
Figures from the consultancy's latest car insurance price index, published in conjunction with price comparison website Confused.com, reveal women drivers aged 17-20 have seen their average comprehensive motor insurance premiums increase by over £500, to £2,256, for an annual policy.
Over the same period, men aged 17-20 have seen their average premium for comprehensive cover fall by an average of 14%, or £466, to £2,848.
Less than a year ago, in September 2012, men aged 17-20 were paying £3,314 on average for their annual cover - nearly double the £1,707 being paid on average by women in the same age group.
The ban on gender-based insurance pricing took effect in December 2012.
Overall, average comprehensive car insurance prices fell by 9.8% over the 12 months to the end of March to £736, with the first three months of this year seeing a decline of 0.1%. The fastest price falls were seen in the South, Southeast and Northeast, while the slowest decline was recorded in Northern Ireland.
Duncan Anderson, head of pricing and product management at Towers Watson, said: 'Price competition is still very strong and margins fragile across the market as a whole, and the Gender Directive has introduced a level of uncertainty in the young driver segment in particular that has caused most insurers to take a cautious approach.
'Companies will be watching their policy portfolios very closely to formulate their next moves.'
The increase in prices for young women was also seen in the smaller percentage of drivers with third party, fire and theft cover, which traditionally includes a high proportion of younger drivers.
Here, overall prices increase by an average of 2.7% in the first quarter of 2013, but for women aged 17-20 prices increased by 20.9%. Young women's third party, fire and theft cover prices have now increased by 43.2% over the past year, compared to an average 1% price increase for the cover as a whole.