Google's chief executive Eric Schmidt said yesterday at the company's annual meeting that the trial had been "successful".
"That's a good basis to talk to Yahoo! some more," he said.
A deal is yet to be made as Yahoo! has been busy fighting off Microsoft. The software giant withdrew its $44.6bn (£22.6bn) bid to acquire Yahoo! on the weekend after the two failed to agree an acceptable price.
Separately, Google declined to reveal any further detail about the several new products for video-sharing site YouTube that it is planning to launch in the next few months.
Schmidt, who mentioned the plans earlier this week, remained tight-lipped about the products but revealed that they have not begun initial or beta testing.
He said that getting YouTube to make money is Google's top priority for the year.