It is not known whether incumbent agency Tamar repitched.
Mark Attwell, associate director, ecommerce at Comparethemarket.com said: "We work with specialists in different areas of our business, and were attracted to Steak’s transparent approach and proven track record in delivering results quickly."
Comparethemarket.com was launched in 2006 as a motor insurance comparison site, offering insurance quotes instantly online, from more than 400 insurance prices.
Comparethemarket.com has developed the brand with its , created by VCCP.
Yesterday (28 September) had retained its £15m media account.