Yahoo and eBay have agreed upon a partnership to extend their exposure. This was believed as a move to withstand Google’s encroachment. The multi-year deal is set to begin testing over the next several months will a full roll-out later this year.

Yahoo becomes eBay’s only provider of graphical ads, as well as sponsored search advertisements. In return PayPal, an eBay company, will be the exclusive payment service across Yahoo’s e-commerce and advertiser networks. That includes the Yahoo Publisher Network, Yahoo Search Marketing, Yahoo Merchant Solutions and other small business services.

Furthermore, the two companies will begin developing click-to-call advertising using both Yahoo Messenger’ voice function and eBay’s Skype service.

eBay will also feature Yahoo on their toolbar, with integrated Yahoo network links and search box.