
The company described the move as the biggest redesign in its history, and promised that the new homepages would focus on search, content, community and personalisation.
The internet search portal hopes to attract more advertising by making the opportunities more appealing to prospective buyers.
Advertisers will now be able to buy a spot within Yahoo Marketplace, which includes cars, travel and shopping.
"This spot will provide an image and a direct contextually-relevant link designed to drive users through to the advertiser's website," said a Yahoo statement.
Blake Chandlee, UK commercial director at Yahoo UK and Ireland, added: "The new Yahoo homepage is an exciting new proposition for advertisers to interact more with their target market and allow the user to engage more with their brands."
Yahoo claimed that the audience for the site has been growing, with daily average page views showing year-on-year growth of 41 per cent, according to May figures from Nielsen//NetRatings.
The redesign will include frequent updates throughout the day and is expected to encourage users to spend more time on the site.
The new homepage also includes Yahoo Answers, as well as the mail and messenger service so that users can access their inbox and IM friends without needing to log in to separate websites.