If you hold a valid French license, you should be able to exchange it for a UK license. However, you will need to surrender your Frence license to do this. You cannot hold both licenses simultaneously. Here is a little question and answer thing that will let you know if you are eligible for an exchange without taking the UK driving test: http://www.direct.gov.uk/en/Diol1/Motor ... icence.dsb

However, I think you will find that this may not have a huge effect on your insurance rates because you may still be considered an "unexperienced UK driver". My suggestion would be to call an insurance broker in the UK and get them to give you a quote with your French license and with a UK license and see if it would be worth exchanging for a UK one.