Google and Yahoo have announced a new internet marketing deal.

The two search engines have reached a landmark advertising agreement that will see Yahoo displaying Google adverts alongside their own listings.

Yahoo chief executive, Jerry Lang, described the new deal as "the next major development" in search engine marketing.

He said: "We believe that the convergence of search and display is the next major development in the evolution of the rapidly changing online advertising industry.

"Our strategies are specifically designed to capitalise on this convergence - and this agreement helps us move them forward."

The two companies have also agreed to increase the interoperability of their instant messaging.

According to the Wall Street Journal, some experts are concerned that the new deal will result in higher advertising rates and less control over where adverts are displayed.

What implication could such a deal have for search engine marketing?

Online Marketing specialists Business Feet help create value from business websites