Introducing the devil's advocate

Yahoo has announced plans to carry search advertising from Google as part of a "test partnership."

The experiment, whereby Google ads appear alongside Yahoo search results, will last two weeks and apply to US-based Yahoo users.

The move closely follows Microsoft's failed attempt to scare Yahoo with an ultimatum on its $44.6 billion buyout bid.

The New York Times says a successful ad relationship with Google may justify a higher offer from Yahoo suitors. Analysts believe outsourcing search ads to Google will boost Yahoo's cash flow, but few are optimistic that it will ultimately drive Microsoft's offer up.

The Wall Street Journal speculates it may just irritate Microsoft, whose initial advances were rebuffed after Google expressed negative feelings about the offer.

It is uncertain whether its trial relationship with Yahoo means Google may want to buy it, though Microsoft may be incited to increase its bid if it thinks Google is moving in on the deal.

"Our proposal remains the only alternative put forward that offers Yahoo shareholders full and fair value for their shares, gives every shareholder a vote on the future of the company, and enhances choice for content creators, advertisers, and consumers," Microsoft was quoted as saying.