Yahoo has not revealed how much it is spending in each market. The campaign will run in the US, India, France, Brazil, Canada, Hong Kong, Indonesia, Korea and Taiwan. Its Asia roll-out is expected before the end of the year.
Yahoo's redesigned homepage, which features a greater degree of personalisation and incorporates links to social networking sites such as Facebook, goes live today having been in beta for a short period.
The global campaign is focused on personalisation and how consumers can access multiple services and information online. It will run until the end of 2010.
The integrated activity is underpinned by a strong digital element that will kick off with a cross-platform campaign.
Yahoo will run online ads across its network, mobile sites and the homepage - expandable banners will demonstrate how to take the "Y!OU" web experience on the go.
In addition, Yahoo Search will include video ads and key products when people search for branded keywords on the search engine and Yahoo Mobile will offers users ringtones featuring the 'Yahoo yodel' for download.