Google’s grip on the search market shows no sign of slipping as they put the finishing touches to a controversial search advertising partnership with long-term rival Yahoo.

The deal was originally announced in June of this year and once finalised will allow Google to sell advertising for some of Yahoo’s online advertising space. Their coming together has been very unpopular with online advertisers who fear higher prices as a result.

For industry experts the deal is widely seen as an effort by Google to fend off Microsoft’s efforts to acquire Yahoo, by bringing Yahoo an additional $800 million in annual revenues. If successful the deal will further strengthen Google’s market position.

Indeed, recent research by comScore Inc has shown Google’s web-search market share widen to 63 percent in August, while Yahoo dropped to 19.6 percent and Microsoft slipped to 8.3 percent.

Whilst both companies have recently agreed to US regulators’ requests to look into the proposed contract this is not expected to delay the deal beyond the end of this month.